Callisto’s Ocean Secrets, Lasers Unveiling Mars’ Past Life, and ISS Cleanliness Concerns: S28E29

WEBVTT
Kind: captions
Language: en

00:00:00.399 --> 00:00:03.550
this is spacetime series 28 episode 29


00:00:03.560 --> 00:00:06.150
for broadcast on the 7th of March


00:00:06.160 --> 00:00:09.030
2025 coming up on space time could


00:00:09.040 --> 00:00:11.509
Jupiter's moon Kalisto be another Ocean


00:00:11.519 --> 00:00:14.470
World using lasers to try and identify


00:00:14.480 --> 00:00:17.310
ancient Life on Mars and claims the


00:00:17.320 --> 00:00:18.790
International Space Station's


00:00:18.800 --> 00:00:21.070
cleanliness might be making its crew


00:00:21.080 --> 00:00:25.310
sick all that and more coming up on


00:00:25.320 --> 00:00:28.470
SpaceTime welcome to SpaceTime with


00:00:28.480 --> 00:00:38.170
steuart Gary


00:00:38.180 --> 00:00:45.430
[Music]


00:00:45.440 --> 00:00:47.389
as astronomers explore more and more of


00:00:47.399 --> 00:00:49.150
the arter solar system they're finding


00:00:49.160 --> 00:00:50.990
that ocean worlds appear to be quite


00:00:51.000 --> 00:00:53.270
common and now there's another that they


00:00:53.280 --> 00:00:55.510
can add to that growing list the Jovian


00:00:55.520 --> 00:00:58.590
Moon Kalisto if confirmed Kalisto will


00:00:58.600 --> 00:01:00.590
join the likes of gany me Europa


00:01:00.600 --> 00:01:03.790
Enceladus Titan Triton Series and Pluto


00:01:03.800 --> 00:01:05.550
to name just a few which are all thought


00:01:05.560 --> 00:01:07.310
to have liquid water oceans beneath


00:01:07.320 --> 00:01:10.469
their icy crusts Kalisto is Jupiter's


00:01:10.479 --> 00:01:12.830
second biggest Galilean Moon and it's


00:01:12.840 --> 00:01:14.550
more pip Mark with crators than just


00:01:14.560 --> 00:01:16.270
about any other object in our solar


00:01:16.280 --> 00:01:19.270
system NASA's Galileo spacecraft back in


00:01:19.280 --> 00:01:21.749
the 1990s captured magnetic measurements


00:01:21.759 --> 00:01:23.830
of Kalisto suggesting its ey shell


00:01:23.840 --> 00:01:26.190
surface may be covering a salty liquid


00:01:26.200 --> 00:01:28.469
water ocean but the evidence has


00:01:28.479 --> 00:01:29.950
actually remained fairly inconclusive


00:01:29.960 --> 00:01:32.310
inclusive that's because Kalisto has an


00:01:32.320 --> 00:01:35.270
intense ionosphere now a new study


00:01:35.280 --> 00:01:37.630
reported in the journal agu advances has


00:01:37.640 --> 00:01:39.710
provided a more in-depth review of the


00:01:39.720 --> 00:01:42.190
data examining all eight of Galileo's


00:01:42.200 --> 00:01:44.429
close flybys of Kalisto which more


00:01:44.439 --> 00:01:46.910
strongly suggests that kisto does in


00:01:46.920 --> 00:01:49.429
fact Harbor a subsurface ocean but as


00:01:49.439 --> 00:01:51.310
well as looking at the flyby data the


00:01:51.320 --> 00:01:53.030
authors of the study also undertook more


00:01:53.040 --> 00:01:54.789
advanced computer modeling of kalista's


00:01:54.799 --> 00:01:56.789
ionosph as well as its geophysical


00:01:56.799 --> 00:01:58.789
properties in order to determine if a


00:01:58.799 --> 00:02:01.029
subsurface ocean is compatible with the


00:02:01.039 --> 00:02:03.230
available information they found


00:02:03.240 --> 00:02:05.469
kalista's osphere alone couldn't explain


00:02:05.479 --> 00:02:07.709
all the existing observations but that a


00:02:07.719 --> 00:02:09.790
subsurface ocean in combination with the


00:02:09.800 --> 00:02:12.150
moon's ionosphere could the authors


00:02:12.160 --> 00:02:14.229
think kalisto's ocean is likely to be at


00:02:14.239 --> 00:02:16.990
least several tens of kilometers deep


00:02:17.000 --> 00:02:19.509
it's encased beneath a solid ice shell


00:02:19.519 --> 00:02:21.430
that itself could range from tens to


00:02:21.440 --> 00:02:23.869
hundreds of kilometers thick these new


00:02:23.879 --> 00:02:25.190
findings are setting the stage for


00:02:25.200 --> 00:02:27.270
additional Studies by both NASA's Europa


00:02:27.280 --> 00:02:29.190
clippa spacecraft and the European space


00:02:29.200 --> 00:02:31.949
agency's Ed Jupiter icy moons Explorer


00:02:31.959 --> 00:02:33.949
Mission both of which are currently on


00:02:33.959 --> 00:02:37.070
their way to the Jovian system needless


00:02:37.080 --> 00:02:40.830
to say we'll keep you informed this is


00:02:40.840 --> 00:02:43.790
spacetime still to come using lasers to


00:02:43.800 --> 00:02:46.350
try and identify Life on Mars and a new


00:02:46.360 --> 00:02:48.149
study suggests that the International


00:02:48.159 --> 00:02:50.350
Space Station's cleanliness might be


00:02:50.360 --> 00:02:52.630
making its crew sick all that and more


00:02:52.640 --> 00:02:57.730
coming up on SpaceTime


00:02:57.740 --> 00:03:09.830
[Music]


00:03:09.840 --> 00:03:11.990
a new study suggest that lasers could be


00:03:12.000 --> 00:03:14.229
used to try and identify the fossils of


00:03:14.239 --> 00:03:16.789
ancient microbial life on the red planet


00:03:16.799 --> 00:03:19.110
Mars the idea comes about because


00:03:19.120 --> 00:03:20.710
scientists have now successfully used


00:03:20.720 --> 00:03:23.589
lasers to identify microbial fossils in


00:03:23.599 --> 00:03:26.309
Gypsum rocks here on Earth and because


00:03:26.319 --> 00:03:28.149
gypsum samples on Earth are a close


00:03:28.159 --> 00:03:30.670
analog for sulfate rocks on on Mars it


00:03:30.680 --> 00:03:32.509
raises the possibility of also using


00:03:32.519 --> 00:03:34.589
lasers to search for fossils on the red


00:03:34.599 --> 00:03:37.110
planet billions of years ago water on


00:03:37.120 --> 00:03:39.309
Mars dried up and gypsum and other


00:03:39.319 --> 00:03:41.190
sulfates were formed when pools


00:03:41.200 --> 00:03:43.229
evaporated leaving behind minerals that


00:03:43.239 --> 00:03:44.990
precipitated out of the water and


00:03:45.000 --> 00:03:47.429
potentially fossilized any organic life


00:03:47.439 --> 00:03:49.869
that may have existed there this means


00:03:49.879 --> 00:03:52.030
that if microbes such as bacteria lived


00:03:52.040 --> 00:03:54.190
on Mars traces of their presence could


00:03:54.200 --> 00:03:56.069
be preserved as Martian


00:03:56.079 --> 00:03:58.270
fossils now according to the authors


00:03:58.280 --> 00:04:00.229
gypsum deposits formed on Ms could


00:04:00.239 --> 00:04:02.390
conceal evidence of past life on the red


00:04:02.400 --> 00:04:04.509
planet microbes similar to that first


00:04:04.519 --> 00:04:06.309
life that formed on Earth 4 billion


00:04:06.319 --> 00:04:08.949
years ago so how did they reach their


00:04:08.959 --> 00:04:10.990
conclusions well the author selected a


00:04:11.000 --> 00:04:12.429
miniature laser powered Mass


00:04:12.439 --> 00:04:14.030
spectrometer that was light enough to


00:04:14.040 --> 00:04:16.390
travel on a spacecraft yet capable of


00:04:16.400 --> 00:04:18.270
analyzing the chemical composition of a


00:04:18.280 --> 00:04:20.870
sample in detail as fine as just one


00:04:20.880 --> 00:04:23.310
micrometer they sample gypsum from a


00:04:23.320 --> 00:04:25.830
quaran Algeria analyzing it using a mass


00:04:25.840 --> 00:04:27.950
spectrometer and an optical microscope


00:04:27.960 --> 00:04:29.909
Guided by criteria which can help


00:04:29.919 --> 00:04:31.870
distinguish between potential microbial


00:04:31.880 --> 00:04:34.510
fossils and natural rock formations


00:04:34.520 --> 00:04:35.950
these include morphology which is


00:04:35.960 --> 00:04:38.790
irregular sinuous and potentially Hollow


00:04:38.800 --> 00:04:40.189
as well as the presence of chemical


00:04:40.199 --> 00:04:42.510
elements necessary for Life carbonaceous


00:04:42.520 --> 00:04:44.350
material and minerals like clay or


00:04:44.360 --> 00:04:46.230
Dolomite which can be influenced by the


00:04:46.240 --> 00:04:48.790
presence of bacteria they successfully


00:04:48.800 --> 00:04:50.550
identified long twisting fossil


00:04:50.560 --> 00:04:52.310
filaments within the Algerian gypsum


00:04:52.320 --> 00:04:53.870
which have previously been interpreted


00:04:53.880 --> 00:04:56.029
as cob bacteria and are now thought to


00:04:56.039 --> 00:04:58.990
be sulfur oxidizing bacteria these were


00:04:59.000 --> 00:05:01.029
embedded in the gypsum and surrounded by


00:05:01.039 --> 00:05:04.150
dite clay minerals and pyite the


00:05:04.160 --> 00:05:05.550
presence of these minerals in the earth


00:05:05.560 --> 00:05:07.670
rocks signals the presence of organic


00:05:07.680 --> 00:05:09.990
life because procaryotes without a


00:05:10.000 --> 00:05:12.430
nucleus Supply Elements which Clays need


00:05:12.440 --> 00:05:14.870
to form and that also facilitate


00:05:14.880 --> 00:05:16.710
Dolomite formation in an acidic


00:05:16.720 --> 00:05:18.790
environment like Ms by increasing the


00:05:18.800 --> 00:05:20.790
alkalinity around them and concentrating


00:05:20.800 --> 00:05:23.950
ions in their cell envelopes for dite to


00:05:23.960 --> 00:05:25.710
form within gypsum without the presence


00:05:25.720 --> 00:05:27.550
of organic life extremely high


00:05:27.560 --> 00:05:28.790
temperatures and pressures would be


00:05:28.800 --> 00:05:30.510
needed that would have dehydrated the


00:05:30.520 --> 00:05:32.189
gypsum and these simply are not


00:05:32.199 --> 00:05:33.629
consistent with our knowledge of the


00:05:33.639 --> 00:05:36.070
Martian environment a report in the


00:05:36.080 --> 00:05:37.830
Journal of the Frontiers and astronomy


00:05:37.840 --> 00:05:39.870
and space Sciences claims that if Mass


00:05:39.880 --> 00:05:41.870
spectrometers can identify the presence


00:05:41.880 --> 00:05:44.270
of Clays and Dolomite in Martian gypson


00:05:44.280 --> 00:05:46.309
in addition to other bios signatures


00:05:46.319 --> 00:05:48.990
this could be a key signal of fossilized


00:05:49.000 --> 00:05:50.590
ancient Life on


00:05:50.600 --> 00:05:52.670
Mars This is


00:05:52.680 --> 00:05:55.150
spacetime still to come a new study


00:05:55.160 --> 00:05:56.430
suggest the International Space


00:05:56.440 --> 00:05:58.510
Station's cleanliness might be making


00:05:58.520 --> 00:06:01.469
its crew sick and the Mars Equinox the


00:06:01.479 --> 00:06:03.230
constellations of tourist the bull and


00:06:03.240 --> 00:06:05.390
Leo the Lion and don't forget it's


00:06:05.400 --> 00:06:06.790
almost


00:06:06.800 --> 00:06:09.629
3.14159 that's Pi Day all that and more


00:06:09.639 --> 00:06:12.120
coming up on MCH


00:06:12.130 --> 00:06:25.150
[Music]


00:06:25.160 --> 00:06:27.390
Skywatch a new study suggest the


00:06:27.400 --> 00:06:28.749
International Space Station's


00:06:28.759 --> 00:06:30.950
cleanliness might be making its crew


00:06:30.960 --> 00:06:33.830
sick astronauts often experience immune


00:06:33.840 --> 00:06:35.749
dysfunction skin rashes and other


00:06:35.759 --> 00:06:37.430
inflammatory conditions while traveling


00:06:37.440 --> 00:06:40.430
in space now a new study reported in the


00:06:40.440 --> 00:06:42.510
journal cell suggests that these issues


00:06:42.520 --> 00:06:44.870
are likely due to the overly sterile


00:06:44.880 --> 00:06:46.309
nature of the International Space


00:06:46.319 --> 00:06:48.270
Station the authors believe the


00:06:48.280 --> 00:06:50.110
introduction of a higher diversity of


00:06:50.120 --> 00:06:51.950
microbes on the station could


00:06:51.960 --> 00:06:53.990
counterintuitively improve the health of


00:06:54.000 --> 00:06:55.469
people living aboard the orbiting


00:06:55.479 --> 00:06:58.189
Outpost to work this out the authors got


00:06:58.199 --> 00:06:59.749
the crew of the International Space


00:06:59.759 --> 00:07:01.749
station to collect more than 800 samples


00:07:01.759 --> 00:07:03.390
from around the station and then bring


00:07:03.400 --> 00:07:06.150
them back to Earth they then identified


00:07:06.160 --> 00:07:07.990
which bacterial species in chemicals


00:07:08.000 --> 00:07:10.029
were present they found there were far


00:07:10.039 --> 00:07:11.909
fewer Free Living microbes on the


00:07:11.919 --> 00:07:13.710
station and the author suggest the


00:07:13.720 --> 00:07:15.629
intentional introduction of more of them


00:07:15.639 --> 00:07:17.150
could help improve the astronaut's


00:07:17.160 --> 00:07:20.350
Health without sacrificing hygiene this


00:07:20.360 --> 00:07:23.810
is spacetime


00:07:23.820 --> 00:07:30.300
[Music]




00:07:37.639 --> 00:07:39.309
and time now to turn our eyes to the


00:07:39.319 --> 00:07:41.189
skies and check out the celestial sphere


00:07:41.199 --> 00:07:44.629
for March on Skywatch happy New Year


00:07:44.639 --> 00:07:46.230
well it would be if this was ancient


00:07:46.240 --> 00:07:49.070
Mesopotamia or Rome that's because March


00:07:49.080 --> 00:07:50.790
was the first month of the New Year


00:07:50.800 --> 00:07:52.710
going back to the earliest concept of


00:07:52.720 --> 00:07:54.469
celebrating New Year's Day at the time


00:07:54.479 --> 00:07:58.589
of the vernal equinox around 2000 BC see


00:07:58.599 --> 00:08:00.110
the ancient Roman calendar which had


00:08:00.120 --> 00:08:02.670
just 10 months designated March 1st as


00:08:02.680 --> 00:08:05.430
the new year that 10-month calendar is


00:08:05.440 --> 00:08:07.830
still reflected today with a name


00:08:07.840 --> 00:08:09.790
September or September being Latin for


00:08:09.800 --> 00:08:12.950
seven October octo meaning 8 November or


00:08:12.960 --> 00:08:15.670
November 9 and December or Des meaning


00:08:15.680 --> 00:08:18.469
10 it wasn't really until the gorian


00:08:18.479 --> 00:08:20.270
calendar that January 1st marked the


00:08:20.280 --> 00:08:22.390
start of the new year but in the


00:08:22.400 --> 00:08:24.270
beginning was mostly Catholic countries


00:08:24.280 --> 00:08:27.110
that adopted it Protestant Nations only


00:08:27.120 --> 00:08:29.469
gradually moved across with the British


00:08:29.479 --> 00:08:31.430
for example not adopting the reformed


00:08:31.440 --> 00:08:33.350
calendar until


00:08:33.360 --> 00:08:35.790
1752 prior to that date the British


00:08:35.800 --> 00:08:38.269
Empire and its American colonies still


00:08:38.279 --> 00:08:41.949
celebrated New Year's Day on March 25th


00:08:41.959 --> 00:08:43.750
the highlight of this month is the March


00:08:43.760 --> 00:08:45.670
Equinox which will take place on the


00:08:45.680 --> 00:08:47.670
evening of Thursday March the 20th


00:08:47.680 --> 00:08:50.310
Australian eastern daylight time that's


00:08:50.320 --> 00:08:52.990
5:01 in the morning of Thursday March 20


00:08:53.000 --> 00:08:56.430
us Easter daylight time and 9:01 a.m. R


00:08:56.440 --> 00:08:58.910
mean time for our listeners in the


00:08:58.920 --> 00:09:01.230
northern hemisphere it means the vernal


00:09:01.240 --> 00:09:03.829
equinox the start of spring although


00:09:03.839 --> 00:09:05.590
south of the Equator it's the autal


00:09:05.600 --> 00:09:08.590
Equinox meaning a move into Autumn the


00:09:08.600 --> 00:09:10.310
day marks the point in Earth's orbit


00:09:10.320 --> 00:09:11.949
around the sun when the planet's


00:09:11.959 --> 00:09:14.230
rotational axis means the sun will


00:09:14.240 --> 00:09:16.750
appear to rise exactly due east and set


00:09:16.760 --> 00:09:18.910
exactly Due West to someone standing on


00:09:18.920 --> 00:09:22.069
the equator it means almost equal hours


00:09:22.079 --> 00:09:24.470
of Darkness and Light in fact the very


00:09:24.480 --> 00:09:26.710
word Equinox is derived from the Latin


00:09:26.720 --> 00:09:29.509
meaning Equis or equal and nox meaning


00:09:29.519 --> 00:09:32.069
night it all comes about because Earth's


00:09:32.079 --> 00:09:34.590
rotational axis is tilted at an angle of


00:09:34.600 --> 00:09:37.030
around 23.4 de in relation to the


00:09:37.040 --> 00:09:38.990
ecliptic the plane created by Earth's


00:09:39.000 --> 00:09:42.030
orbit around the Sun that axial tilt is


00:09:42.040 --> 00:09:43.910
always pointed at the same position in


00:09:43.920 --> 00:09:46.269
the sky regardless of Earth's orbital


00:09:46.279 --> 00:09:49.030
position around the Sun so on any other


00:09:49.040 --> 00:09:50.870
day of the year either the Northern or


00:09:50.880 --> 00:09:52.389
Southern Hemisphere it tilted more


00:09:52.399 --> 00:09:55.389
towards the Sun but on the two equinoxes


00:09:55.399 --> 00:09:57.829
usually around March 21st and September


00:09:57.839 --> 00:10:00.350
23rd each year the two of Earth's axis


00:10:00.360 --> 00:10:02.870
is directly perpendicular to the sun's


00:10:02.880 --> 00:10:05.110
Rays however there's a complication


00:10:05.120 --> 00:10:07.630
called procession this causes earth spin


00:10:07.640 --> 00:10:09.790
axis to wobble ever so slightly just


00:10:09.800 --> 00:10:12.389
like the axle of a spinning top the rate


00:10:12.399 --> 00:10:14.069
of procession is only about half a


00:10:14.079 --> 00:10:15.949
degree per Century so people don't


00:10:15.959 --> 00:10:18.509
notice it on human time scales and


00:10:18.519 --> 00:10:20.310
because the direction of Earth's axis of


00:10:20.320 --> 00:10:22.190
rotation determines at which point in


00:10:22.200 --> 00:10:24.590
Earth's orbit Seasons occur procession


00:10:24.600 --> 00:10:26.550
will cause a particular season for


00:10:26.560 --> 00:10:28.430
example the southern hemisphere Autumn


00:10:28.440 --> 00:10:30.150
to occur at a slight slightly different


00:10:30.160 --> 00:10:33.030
place from year to year over 21,000 year


00:10:33.040 --> 00:10:36.030
cycle at the same time Earth orbit


00:10:36.040 --> 00:10:38.110
itself is subjected to small changes


00:10:38.120 --> 00:10:40.870
called pertubations see Earth's orbits


00:10:40.880 --> 00:10:43.389
in ellipse and there's a slow change in


00:10:43.399 --> 00:10:45.670
its orientation which gradually shifts


00:10:45.680 --> 00:10:47.710
the point of parhelion Earth's closest


00:10:47.720 --> 00:10:50.230
orbital position to the sun now these


00:10:50.240 --> 00:10:52.430
two effects the procession of the axis


00:10:52.440 --> 00:10:54.629
of rotation and the change in the orbits


00:10:54.639 --> 00:10:57.030
orientation work together to shift the


00:10:57.040 --> 00:10:59.790
seasons with respect to parhelion


00:10:59.800 --> 00:11:01.150
and because we use a calendar year


00:11:01.160 --> 00:11:02.550
that's aligned to the occurrence of the


00:11:02.560 --> 00:11:05.150
seasons the date of perhelion gradually


00:11:05.160 --> 00:11:08.269
regresses through a 21,000 year cycle


00:11:08.279 --> 00:11:10.430
and there's another complication


00:11:10.440 --> 00:11:11.750
Australia and some of the other


00:11:11.760 --> 00:11:13.310
commonwealth countries start their


00:11:13.320 --> 00:11:15.470
seasons on the first day of the month


00:11:15.480 --> 00:11:17.350
what are referred to as meteorological


00:11:17.360 --> 00:11:19.710
Seasons rather than on the Soler season


00:11:19.720 --> 00:11:21.550
equinoxes which are referred to as


00:11:21.560 --> 00:11:24.350
astronomical Seasons so that means


00:11:24.360 --> 00:11:26.230
Australia's Autumn officially began on


00:11:26.240 --> 00:11:28.150
March 1st rather than on the day of the


00:11:28.160 --> 00:11:31.030
March Equinox meteorological seasons are


00:11:31.040 --> 00:11:32.509
used because it makes it easier for


00:11:32.519 --> 00:11:34.470
meteorologists and climatologists to


00:11:34.480 --> 00:11:36.509
break the seasons down into more exact


00:11:36.519 --> 00:11:38.829
3month calendar groupings for comparing


00:11:38.839 --> 00:11:40.470
seasonal and monthly


00:11:40.480 --> 00:11:42.430
statistics the moment of the March


00:11:42.440 --> 00:11:45.030
Equinox is also important in astronomy


00:11:45.040 --> 00:11:46.430
because it's used to define the


00:11:46.440 --> 00:11:48.430
celestial coordinate system of right


00:11:48.440 --> 00:11:51.430
Ascension and declination in astronomy


00:11:51.440 --> 00:11:53.150
the celestial coordinate system is the


00:11:53.160 --> 00:11:55.110
astronomical equivalent to the latitude


00:11:55.120 --> 00:11:56.949
and longitudinal coordinates used on


00:11:56.959 --> 00:11:59.230
Earth's surface it's used to spef


00:11:59.240 --> 00:12:00.710
specify the position of objects in


00:12:00.720 --> 00:12:02.350
three-dimensional space and the


00:12:02.360 --> 00:12:03.629
direction of those objects on the


00:12:03.639 --> 00:12:05.949
celestial sphere the imaginary Globe


00:12:05.959 --> 00:12:07.990
surrounding the earth in other words it


00:12:08.000 --> 00:12:09.430
lets scientists determine the position


00:12:09.440 --> 00:12:11.069
of a celestial object such as a


00:12:11.079 --> 00:12:13.750
satellite a planet Stars galaxies and so


00:12:13.760 --> 00:12:16.509
on right Ascension which uses the symbol


00:12:16.519 --> 00:12:18.509
Alpha is the angular distance measured


00:12:18.519 --> 00:12:20.350
eastwards along the celestial equator


00:12:20.360 --> 00:12:23.230
from the vernal equinox on the celestial


00:12:23.240 --> 00:12:25.389
sphere it's analogous to terrestrial


00:12:25.399 --> 00:12:27.949
longitude declination which uses the


00:12:27.959 --> 00:12:30.030
symbol Delta measur is the angle north


00:12:30.040 --> 00:12:32.389
or south of the celestial equator and so


00:12:32.399 --> 00:12:33.949
it's the celestial equivalent to


00:12:33.959 --> 00:12:35.389
terrestrial


00:12:35.399 --> 00:12:38.030
latitude marking the veral equinox and


00:12:38.040 --> 00:12:39.829
setting the Western evening sky this


00:12:39.839 --> 00:12:41.550
time of year is one of the oldest


00:12:41.560 --> 00:12:43.790
recognized constellations in the heavens


00:12:43.800 --> 00:12:46.790
Taurus the Bull so named around 6,000


00:12:46.800 --> 00:12:49.710
years ago in Greek mythology Taurus


00:12:49.720 --> 00:12:52.790
represents the king of the god Zeus Zeus


00:12:52.800 --> 00:12:55.310
lasted after King ao's Daughter Europa


00:12:55.320 --> 00:12:57.629
who was looking after a herd of cattle


00:12:57.639 --> 00:13:00.189
now being a God and with Godlike Powers


00:13:00.199 --> 00:13:02.670
Zeus decided to transform himself into a


00:13:02.680 --> 00:13:05.030
powerful white ball so that he could get


00:13:05.040 --> 00:13:07.670
closer to the beautiful Europa now once


00:13:07.680 --> 00:13:10.030
transformed into a bull Zeus convinced


00:13:10.040 --> 00:13:12.069
Europa to climb on his back and he then


00:13:12.079 --> 00:13:14.389
carried her off to the island of creit


00:13:14.399 --> 00:13:16.269
Taurus's head is represented by a


00:13:16.279 --> 00:13:19.150
dominant v-shaped grouping of stars the


00:13:19.160 --> 00:13:20.829
bright reddish star in the group is


00:13:20.839 --> 00:13:23.829
alaran an orange giant one a half times


00:13:23.839 --> 00:13:26.230
the mass of the Sun located 65 light


00:13:26.240 --> 00:13:28.710
years away a lightyear is about 10


00:13:28.720 --> 00:13:31.470
trillion kilm the distance of feron can


00:13:31.480 --> 00:13:34.509
travel in a year at 300,000 km/ second


00:13:34.519 --> 00:13:36.389
the speed of light in a vacuum and the


00:13:36.399 --> 00:13:38.750
ultimate speed limit of the universe


00:13:38.760 --> 00:13:41.110
albran is the 14th brightest star in the


00:13:41.120 --> 00:13:43.430
night sky and the closest bright star to


00:13:43.440 --> 00:13:45.870
the point of the vernal equinox in


00:13:45.880 --> 00:13:48.230
ancient Arabic aut Bran's name means the


00:13:48.240 --> 00:13:50.069
follower as it appears to follow the


00:13:50.079 --> 00:13:53.189
Seven Sisters of the ples it's also the


00:13:53.199 --> 00:13:54.949
first of the four royal or Guardian


00:13:54.959 --> 00:13:57.509
Stars identified by the ancient


00:13:57.519 --> 00:13:59.870
Mesopotamians now that v-shaped grouping


00:13:59.880 --> 00:14:03.389
of stars near uran is known as the hies


00:14:03.399 --> 00:14:05.470
it's the nearest young open star cluster


00:14:05.480 --> 00:14:08.550
to Earth located just 153 light years


00:14:08.560 --> 00:14:11.350
away between utaran and the Orion


00:14:11.360 --> 00:14:13.550
constellation you'll see a bright red


00:14:13.560 --> 00:14:16.030
star that's bleo the ninth brightest


00:14:16.040 --> 00:14:18.150
star in the night sky these days more


00:14:18.160 --> 00:14:20.829
commonly called Beetle Juice if you turn


00:14:20.839 --> 00:14:22.670
to the north now you'll see the two


00:14:22.680 --> 00:14:25.069
bright stars polax and Casta which


00:14:25.079 --> 00:14:27.189
represent the northern constellation of


00:14:27.199 --> 00:14:29.910
Gemini the twins in Greek mythology they


00:14:29.920 --> 00:14:31.790
were brothers who traveled with Jason


00:14:31.800 --> 00:14:33.670
aboard the ship Argo in search of the


00:14:33.680 --> 00:14:36.710
Gordon fleece paax is an orange hued


00:14:36.720 --> 00:14:39.430
evolved giant Star located 34 light


00:14:39.440 --> 00:14:42.310
years away it has about twice the Sun's


00:14:42.320 --> 00:14:44.710
mass and has bloated out to around 11


00:14:44.720 --> 00:14:48.030
times the Sun's diameter in 2006 an


00:14:48.040 --> 00:14:50.110
extra Solar Planet or exoplanet


00:14:50.120 --> 00:14:52.269
designated poax B was discovered


00:14:52.279 --> 00:14:55.069
orbiting the star the planet is a gas


00:14:55.079 --> 00:14:57.990
giant orbiting its host star every 1.61


00:14:58.000 --> 00:15:00.829
Earth years the other star cter is


00:15:00.839 --> 00:15:03.389
located some 51 L years away and it's


00:15:03.399 --> 00:15:05.230
actually a system of six stars


00:15:05.240 --> 00:15:07.870
comprising three eclipsing binaries


00:15:07.880 --> 00:15:09.949
eclipsing binaries are binary star


00:15:09.959 --> 00:15:11.749
systems in which the orbital plane of


00:15:11.759 --> 00:15:13.829
the two stars in the system lies so


00:15:13.839 --> 00:15:15.790
nearly along the line of sight from The


00:15:15.800 --> 00:15:17.670
Observer here on Earth that the stars


00:15:17.680 --> 00:15:20.389
appear to Eclipse each other looking to


00:15:20.399 --> 00:15:21.870
the Northeast now and you'll see the


00:15:21.880 --> 00:15:24.150
star regulars or little King the


00:15:24.160 --> 00:15:25.910
brightest St in the constellation Leo


00:15:25.920 --> 00:15:28.670
the Lion Leo is mentioned by Homer and


00:15:28.680 --> 00:15:31.269
his famous 8th Century BC poem The


00:15:31.279 --> 00:15:34.069
Odyssey according to Greek mythology Leo


00:15:34.079 --> 00:15:36.309
was killed by Hercules as the first of


00:15:36.319 --> 00:15:39.509
his 12 Labors located some 79 light


00:15:39.519 --> 00:15:42.110
years away regulus is a multiple star


00:15:42.120 --> 00:15:44.990
system composed of at least four stars


00:15:45.000 --> 00:15:47.710
regulus a designated alphal leonus is a


00:15:47.720 --> 00:15:49.949
spectroscopic binary comprising a


00:15:49.959 --> 00:15:52.069
rapidly spinning spectral type B blue


00:15:52.079 --> 00:15:54.230
white star around 3 and 1/2 times more


00:15:54.240 --> 00:15:56.949
massive than the sun with some 288 times


00:15:56.959 --> 00:15:59.470
the sun's luminosity and a small


00:15:59.480 --> 00:16:02.430
companion star most likely a white dwarf


00:16:02.440 --> 00:16:04.350
the still a corpse of what once would


00:16:04.360 --> 00:16:06.990
have been a sunlike star the pair take


00:16:07.000 --> 00:16:09.670
about 40 days to orbit each other


00:16:09.680 --> 00:16:11.629
spectroscopic binaries are double star


00:16:11.639 --> 00:16:13.590
systems orbiting each other so closely


00:16:13.600 --> 00:16:15.470
and at such an angle that they can only


00:16:15.480 --> 00:16:17.829
be visually separated from our Viewpoint


00:16:17.839 --> 00:16:19.269
here on Earth at least by their


00:16:19.279 --> 00:16:20.550
spectroscopic


00:16:20.560 --> 00:16:23.430
signatures astronomers describe stars in


00:16:23.440 --> 00:16:25.430
terms of spectral types it's a


00:16:25.440 --> 00:16:26.949
classification system based on


00:16:26.959 --> 00:16:29.110
temperature and characteristics the


00:16:29.120 --> 00:16:31.150
hottest most massive and most luminous


00:16:31.160 --> 00:16:33.829
stars are known as spectr type O blue


00:16:33.839 --> 00:16:36.430
stars they're followed by spectr type B


00:16:36.440 --> 00:16:38.910
blue white stars then spectral type a


00:16:38.920 --> 00:16:41.389
white stars spectral type f whitish


00:16:41.399 --> 00:16:44.110
yellow stars then spectral type G yellow


00:16:44.120 --> 00:16:46.829
stars that's where our sun fits in then


00:16:46.839 --> 00:16:49.350
the spectr type K orang in stars and the


00:16:49.360 --> 00:16:51.550
coolest and least massive of all stars


00:16:51.560 --> 00:16:54.389
are spectral type M red stars commonly


00:16:54.399 --> 00:16:56.990
referred to as red dwarfs each spectral


00:16:57.000 --> 00:16:58.910
classification system is further sub


00:16:58.920 --> 00:17:00.870
divided using a numeric digit to


00:17:00.880 --> 00:17:02.790
represent temperature with zero being


00:17:02.800 --> 00:17:04.870
the hottest and nine the coolest and


00:17:04.880 --> 00:17:06.470
then you add a Roman numeral to


00:17:06.480 --> 00:17:09.949
represent Luminosity so our son


00:17:09.959 --> 00:17:14.029
technically is a g2v or G25 yellow dwarf


00:17:14.039 --> 00:17:16.309
star also included in the Stellar


00:17:16.319 --> 00:17:18.470
classification system are spectral types


00:17:18.480 --> 00:17:21.230
LT and Y which are assigned to failed


00:17:21.240 --> 00:17:23.549
Stars known as brown dwarves some of


00:17:23.559 --> 00:17:25.429
which were born of spectral type M red


00:17:25.439 --> 00:17:27.750
dwarf stars but became Brown dwarves


00:17:27.760 --> 00:17:30.150
after losing some of their Mass Brown


00:17:30.160 --> 00:17:31.990
dwarves fit into a unique category


00:17:32.000 --> 00:17:33.909
between the largest planets which can


00:17:33.919 --> 00:17:36.110
have around 13 times the mass of Jupiter


00:17:36.120 --> 00:17:38.270
and the smallest spectr type M red dwarf


00:17:38.280 --> 00:17:41.230
stars which are around 75 to 80 times


00:17:41.240 --> 00:17:44.990
the mass of Jupiter or about 0.08 solar


00:17:45.000 --> 00:17:47.870
masses the primary star in Alpha leonus


00:17:47.880 --> 00:17:49.950
completes a full rotation around its


00:17:49.960 --> 00:17:52.870
axis in under 16 hours that's incredibly


00:17:52.880 --> 00:17:54.390
quick especially when compared to our


00:17:54.400 --> 00:17:57.350
Sun's 30-day rotational period now this


00:17:57.360 --> 00:17:59.669
gives the primary star an obl appearance


00:17:59.679 --> 00:18:01.390
and it causes what's known as gravity


00:18:01.400 --> 00:18:03.390
darkening meaning its poles are


00:18:03.400 --> 00:18:05.270
considerably hotter and five times


00:18:05.280 --> 00:18:07.470
brighter per unit surface area than its


00:18:07.480 --> 00:18:10.070
equatorial region scientists estimate


00:18:10.080 --> 00:18:12.990
that if it were rotating just 15% faster


00:18:13.000 --> 00:18:15.029
the star's gravity would be insufficient


00:18:15.039 --> 00:18:16.669
to hold it together and it would


00:18:16.679 --> 00:18:19.669
literally spin itself apart located


00:18:19.679 --> 00:18:22.830
further away a regular b c and d which


00:18:22.840 --> 00:18:25.549
are all dim main sequence Stars main


00:18:25.559 --> 00:18:27.510
sequence stars are those undergoing


00:18:27.520 --> 00:18:29.470
hydrogen fusion into helium in their


00:18:29.480 --> 00:18:32.070
core like the sun's currently doing


00:18:32.080 --> 00:18:34.270
regulus B and C are thought to orbit


00:18:34.280 --> 00:18:36.470
each other every 600 Earth years and are


00:18:36.480 --> 00:18:39.230
located around 5,000 astronomical units


00:18:39.240 --> 00:18:42.070
away from regular SE an astronomical


00:18:42.080 --> 00:18:43.950
unit is the average distance between the


00:18:43.960 --> 00:18:46.549
Earth and the Sun around 150 million


00:18:46.559 --> 00:18:50.669
kilm or 8.3 L minutes regular speed is a


00:18:50.679 --> 00:18:53.190
spectr type f white yellow star while


00:18:53.200 --> 00:18:55.510
its companion regular C is a small


00:18:55.520 --> 00:18:58.789
spectr Type M Red Dwarf star regular Ste


00:18:58.799 --> 00:19:00.510
is a bit more of a question mark it's a


00:19:00.520 --> 00:19:02.750
dim star and at least from our point of


00:19:02.760 --> 00:19:04.470
view it appears to be sharing motion


00:19:04.480 --> 00:19:06.430
across the sky with other members in the


00:19:06.440 --> 00:19:08.630
group at the opposite end of the


00:19:08.640 --> 00:19:10.950
constellation of regulus is the star bet


00:19:10.960 --> 00:19:14.190
leonus or debula the horse's tail it's


00:19:14.200 --> 00:19:16.149
aluminous white star thought to be


00:19:16.159 --> 00:19:18.390
spectr type A about half as bright as


00:19:18.400 --> 00:19:20.310
regulus and the third brightest star in


00:19:20.320 --> 00:19:23.190
the constellation Leo be leonus has


00:19:23.200 --> 00:19:25.789
about 1.8 times the mass of the Sun and


00:19:25.799 --> 00:19:28.950
about 15 times the sun's luminosity it's


00:19:28.960 --> 00:19:31.270
suspected of being a dwarf seph or data


00:19:31.280 --> 00:19:33.549
scoy type variable star meaning its


00:19:33.559 --> 00:19:35.750
Luminosity varies very slightly over a


00:19:35.760 --> 00:19:37.230
period of several hours due to


00:19:37.240 --> 00:19:39.750
pulsations on its surface also at the


00:19:39.760 --> 00:19:42.110
other end of Leo other stars theater and


00:19:42.120 --> 00:19:45.149
Lotto leonus the loins of the lion


00:19:45.159 --> 00:19:47.909
theater leonus is about 165 light years


00:19:47.919 --> 00:19:50.830
away it's a very young spectr type a


00:19:50.840 --> 00:19:53.110
white star about 2 and a half times the


00:19:53.120 --> 00:19:56.430
mass of the sun with an age of just 550


00:19:56.440 --> 00:19:59.230
million years the Leona suspect shows


00:19:59.240 --> 00:20:01.190
enhanced absorption lines for metals


00:20:01.200 --> 00:20:02.950
that these elements other than hydrogen


00:20:02.960 --> 00:20:05.549
and helium this increased metallicity


00:20:05.559 --> 00:20:07.990
appears around 12% higher than the sun


00:20:08.000 --> 00:20:10.230
allowing the star to radiate with some


00:20:10.240 --> 00:20:12.549
141 times the Luminosity of the Sun from


00:20:12.559 --> 00:20:14.510
its outer atmosphere at an effective


00:20:14.520 --> 00:20:17.630
temperature of 9350 Kelvin literally


00:20:17.640 --> 00:20:20.390
giving it a white hot glow located some


00:20:20.400 --> 00:20:23.390
79 light years away L leonus is another


00:20:23.400 --> 00:20:25.549
spectroscopic binary consisting of two


00:20:25.559 --> 00:20:28.110
stars orbiting each other every 183


00:20:28.120 --> 00:20:30.630
Earth years is the primary star is a


00:20:30.640 --> 00:20:33.070
spectral type f yellow dwarf star a


00:20:33.080 --> 00:20:34.630
little hotter and more massive than the


00:20:34.640 --> 00:20:37.830
sun algebra or gamma leonus is a binary


00:20:37.840 --> 00:20:39.789
star system with a visible third


00:20:39.799 --> 00:20:42.070
component the two primary stars are


00:20:42.080 --> 00:20:44.789
located 126 light years away and can be


00:20:44.799 --> 00:20:47.470
resolved in a backyard telescope both


00:20:47.480 --> 00:20:49.549
are yellow Giants orbiting each other


00:20:49.559 --> 00:20:52.990
every 600 Earth days the unrelated tury


00:20:53.000 --> 00:20:55.710
star named for leonus is a yellow Tin


00:20:55.720 --> 00:20:57.230
Star which can be seen through


00:20:57.240 --> 00:20:59.950
binoculars it's traditional name algebra


00:20:59.960 --> 00:21:02.390
means the forehead other stars in the


00:21:02.400 --> 00:21:04.630
system include Delta leonus or zosma


00:21:04.640 --> 00:21:06.990
which is a blue white star 58 L is from


00:21:07.000 --> 00:21:09.390
Earth Epsilon leonus a yellow giant some


00:21:09.400 --> 00:21:12.230
251 light is from Earth and Zeta leonus


00:21:12.240 --> 00:21:14.710
an optical Triple Star the brightest


00:21:14.720 --> 00:21:16.990
component is a white giant about 260


00:21:17.000 --> 00:21:18.630
light years from Earth while the second


00:21:18.640 --> 00:21:21.190
brightest star 39 Le owners is widely


00:21:21.200 --> 00:21:23.190
spaced and is located to the south of


00:21:23.200 --> 00:21:25.350
the primary with the third and faintest


00:21:25.360 --> 00:21:28.149
St in the system 35 leonus located to


00:21:28.159 --> 00:21:30.909
the north North also located in Leo is


00:21:30.919 --> 00:21:33.630
tonus visible as a double star through


00:21:33.640 --> 00:21:35.909
binoculars it includes a yellow giant


00:21:35.919 --> 00:21:38.549
located some 621 light years from Earth


00:21:38.559 --> 00:21:41.710
and a binary secondary star 54 leonus a


00:21:41.720 --> 00:21:43.470
pair of blue white stars divisible in


00:21:43.480 --> 00:21:46.390
small telescopes and located 289 light


00:21:46.400 --> 00:21:48.710
years from Earth also in the


00:21:48.720 --> 00:21:51.029
constellation Leo you'll find the Leo


00:21:51.039 --> 00:21:53.230
Triplet a group of three galaxies


00:21:53.240 --> 00:21:58.789
Messier 65 Messier 66 and NGC 3628 all


00:21:58.799 --> 00:22:01.149
appearing relatively close together


00:22:01.159 --> 00:22:05.390
Messier 65 also known as NGC 3623 is an


00:22:05.400 --> 00:22:08.110
intermediate spiral possibly bad spiral


00:22:08.120 --> 00:22:11.830
galaxy about 37 million light years away


00:22:11.840 --> 00:22:15.110
M65 disc appears to be slightly wared


00:22:15.120 --> 00:22:17.070
and a relatively recent burst of star


00:22:17.080 --> 00:22:18.950
formation is suggestive of some


00:22:18.960 --> 00:22:20.510
gravitational interaction with the other


00:22:20.520 --> 00:22:22.669
two galaxies in the Leo triplet possibly


00:22:22.679 --> 00:22:25.870
around 800 million years ago nearby is


00:22:25.880 --> 00:22:30.070
Messier 66 or ngc3 627 another


00:22:30.080 --> 00:22:33.110
intermediate spiral galaxy some 95,000 L


00:22:33.120 --> 00:22:35.789
years wide and about 36 million L years


00:22:35.799 --> 00:22:38.390
away gravitational interaction from its


00:22:38.400 --> 00:22:39.789
past encounters with the neighboring


00:22:39.799 --> 00:22:41.909
galaxies in the triplet has resulted in


00:22:41.919 --> 00:22:43.710
extremely high Central Mass


00:22:43.720 --> 00:22:46.190
concentration a high molecular to atomic


00:22:46.200 --> 00:22:48.549
mass ratio and a resolved non-rotating


00:22:48.559 --> 00:22:50.549
clump of neutral Atomic hydrogen


00:22:50.559 --> 00:22:52.190
apparently removed from one of its


00:22:52.200 --> 00:22:54.710
spiral arms the third member in the


00:22:54.720 --> 00:22:58.990
group is NGC 3628 the hamburger Galaxy


00:22:59.000 --> 00:23:01.230
a spiral galaxy with a spectacular


00:23:01.240 --> 00:23:04.590
300,000 lye long tidal trail of gas and


00:23:04.600 --> 00:23:08.870
stars NGC 3628 is located 35 million


00:23:08.880 --> 00:23:11.510
light years away its most conspicuous


00:23:11.520 --> 00:23:13.710
feature is the broad and obscuring band


00:23:13.720 --> 00:23:15.630
of dust located along the outer edge of


00:23:15.640 --> 00:23:18.149
its spiral arms effectively transecting


00:23:18.159 --> 00:23:20.310
the galaxy to the view from


00:23:20.320 --> 00:23:22.909
Earth other bright well-known galaxies


00:23:22.919 --> 00:23:27.310
in Leo include Messier 95 Messier 96


00:23:27.320 --> 00:23:31.110
Messier 10 5 and NGC


00:23:31.120 --> 00:23:34.830
2903 m95 and m96 are both spiral


00:23:34.840 --> 00:23:37.230
galaxies each about 20 million light


00:23:37.240 --> 00:23:41.669
years from Earth m95 is a b spiral


00:23:41.679 --> 00:23:45.830
another B spiral galaxy is NGC 2903


00:23:45.840 --> 00:23:47.630
which is thought to be very similar in


00:23:47.640 --> 00:23:50.549
size and structure to our own Milky Way


00:23:50.559 --> 00:23:53.230
galaxy it was discovered by William hsel


00:23:53.240 --> 00:23:54.310
in


00:23:54.320 --> 00:23:58.630
1784 close to the m95 m96 pair is is the


00:23:58.640 --> 00:24:00.269
elliptical galaxy


00:24:00.279 --> 00:24:02.710
m105 which is also around 20 million


00:24:02.720 --> 00:24:05.430
light years from Earth okay let's turn


00:24:05.440 --> 00:24:07.549
to the east now and the constellation of


00:24:07.559 --> 00:24:10.269
corvis the crow in Greek mythology


00:24:10.279 --> 00:24:12.310
corvis was a really clever crow in fact


00:24:12.320 --> 00:24:14.750
he could talk to people however after


00:24:14.760 --> 00:24:16.789
refusing to speak to the god Apollo he


00:24:16.799 --> 00:24:19.149
was banished to the sky together with


00:24:19.159 --> 00:24:21.909
crater the cup and Hydra the snake one


00:24:21.919 --> 00:24:24.549
of the bright stars in Hydra is alad the


00:24:24.559 --> 00:24:27.430
solitary one so named because it appears


00:24:27.440 --> 00:24:28.950
all alone in the sky


00:24:28.960 --> 00:24:31.710
Sky okay turning to the Western Horizon


00:24:31.720 --> 00:24:33.870
now and you'll see the star AA in the


00:24:33.880 --> 00:24:35.909
southern tip of the constellation idanis


00:24:35.919 --> 00:24:38.310
the river eridanus is one of the largest


00:24:38.320 --> 00:24:40.590
and longest constellations in the sky


00:24:40.600 --> 00:24:42.990
AKA means The River's End as it marks


00:24:43.000 --> 00:24:45.950
the end of the river idanis located


00:24:45.960 --> 00:24:48.830
around 139 light years away akona is a


00:24:48.840 --> 00:24:51.590
binary star system comprising two stars


00:24:51.600 --> 00:24:54.710
Alpha Arney a and Alpha ridney B one of


00:24:54.720 --> 00:24:56.590
the 10 apparent brightest stars in the


00:24:56.600 --> 00:24:59.630
night sky Alpha ridney a is a young hot


00:24:59.640 --> 00:25:02.909
spectr type B blue star about 6.7 times


00:25:02.919 --> 00:25:05.430
the mass of the sun with a stunning


00:25:05.440 --> 00:25:09.190
3,150 times the sun's Luminosity aka's


00:25:09.200 --> 00:25:11.070
extremely high rotational velocity of


00:25:11.080 --> 00:25:14.430
over 16 km/s gives it an oblate shape


00:25:14.440 --> 00:25:15.909
making it one of the least sperical


00:25:15.919 --> 00:25:17.470
stars in the Milky Way with an


00:25:17.480 --> 00:25:20.350
equatorial diameter some 56% greater


00:25:20.360 --> 00:25:22.950
than its polar diameter this distorted


00:25:22.960 --> 00:25:24.549
shape means the star displays


00:25:24.559 --> 00:25:26.230
significant latitudinal temperature


00:25:26.240 --> 00:25:28.110
variations with its polar temperature


00:25:28.120 --> 00:25:30.149
being being above 20,000 Kelvin while


00:25:30.159 --> 00:25:32.190
its equatorial temperature being much


00:25:32.200 --> 00:25:34.070
further away from the Stiller core is


00:25:34.080 --> 00:25:36.750
only around 10,000 Kelvin those high


00:25:36.760 --> 00:25:38.789
poar temperatures are generating a fast


00:25:38.799 --> 00:25:41.350
polar wind ejecting matter from the Star


00:25:41.360 --> 00:25:43.669
and generating a polar envelope of hot


00:25:43.679 --> 00:25:46.669
gas and plasma the companion star Alpha


00:25:46.679 --> 00:25:49.269
ridney B appears to be a spectr type a


00:25:49.279 --> 00:25:51.230
white star with about twice the mass of


00:25:51.240 --> 00:25:53.870
the Sun the two stars orbit each other


00:25:53.880 --> 00:25:56.830
at an average distance of roughly 12.3


00:25:56.840 --> 00:25:59.710
astronomical units


00:25:59.720 --> 00:26:01.549
now just a quick reminder that March


00:26:01.559 --> 00:26:04.310
14th marks the yearly celebration of the


00:26:04.320 --> 00:26:07.669
mathematical constant Pi Pi is the ratio


00:26:07.679 --> 00:26:09.470
of a circle circumference to its


00:26:09.480 --> 00:26:12.070
diameter but it's also an irrational


00:26:12.080 --> 00:26:13.590
number meaning its decimal


00:26:13.600 --> 00:26:15.750
representation never ends and never


00:26:15.760 --> 00:26:18.590
repeats more than just a number Pi has


00:26:18.600 --> 00:26:20.710
important applications in astrophysics


00:26:20.720 --> 00:26:22.870
orbital mechanics and other fields of


00:26:22.880 --> 00:26:25.430
astronomy it's been calculated to over a


00:26:25.440 --> 00:26:27.549
trillion digits and the current record


00:26:27.559 --> 00:26:29.870
for reciting ire from memory is over


00:26:29.880 --> 00:26:32.870
70,000 digits imagine sitting next to


00:26:32.880 --> 00:26:36.269
that person at a dinner party as for me


00:26:36.279 --> 00:26:39.549
3.14159 is about it of course as well as


00:26:39.559 --> 00:26:42.630
P day March 14 is also the birthday of


00:26:42.640 --> 00:26:45.630
the great Professor Dr Albert Einstein


00:26:45.640 --> 00:26:47.190
and joining us now for the rest of our


00:26:47.200 --> 00:26:49.350
tour of the March night skies is science


00:26:49.360 --> 00:26:51.870
writer Jonathan allly good St well you


00:26:51.880 --> 00:26:53.470
know I reckon this is a fantastic time


00:26:53.480 --> 00:26:55.510
of the year for stargazing March because


00:26:55.520 --> 00:26:56.870
where I live in the southern hemisphere


00:26:56.880 --> 00:26:58.590
we're just coming out of summer so the


00:26:58.600 --> 00:27:00.070
weather is still good and the nights are


00:27:00.080 --> 00:27:01.510
still warm enough for getting outside


00:27:01.520 --> 00:27:02.870
and looking up for our friends in the


00:27:02.880 --> 00:27:04.990
north their wintry conditions are still


00:27:05.000 --> 00:27:06.789
biting perhaps but the sites you can see


00:27:06.799 --> 00:27:08.870
in March are well worth enduring even


00:27:08.880 --> 00:27:10.389
the cooler nighttime conditions that you


00:27:10.399 --> 00:27:11.510
still have because there are lots of


00:27:11.520 --> 00:27:12.830
great things to see and we'll start in


00:27:12.840 --> 00:27:14.669
the northern part of the sky as seen


00:27:14.679 --> 00:27:16.350
from down here south of the Equator and


00:27:16.360 --> 00:27:17.830
the first thing we spot of course is the


00:27:17.840 --> 00:27:19.789
mighty constellation Orion it's one of


00:27:19.799 --> 00:27:21.789
the most easily recognizable


00:27:21.799 --> 00:27:23.630
constellations for start it's got these


00:27:23.640 --> 00:27:25.750
three stars in a row you can't miss them


00:27:25.760 --> 00:27:26.990
I mean you might think oh you can look


00:27:27.000 --> 00:27:28.350
up and see any three stars in a row with


00:27:28.360 --> 00:27:29.590
these three stars are very close


00:27:29.600 --> 00:27:30.950
together and in a straight line and


00:27:30.960 --> 00:27:32.590
that's known as the belt of Orion


00:27:32.600 --> 00:27:34.590
because Orion mythology of Orion Orion


00:27:34.600 --> 00:27:36.070
is the hunter so there's a big hunter up


00:27:36.080 --> 00:27:37.830
in the sky so this is around his middle


00:27:37.840 --> 00:27:39.350
this is his belt and extending


00:27:39.360 --> 00:27:42.149
southwards from the belt are a few stars


00:27:42.159 --> 00:27:44.230
and a little fuzzy patch and together


00:27:44.240 --> 00:27:45.669
that's known as The Sword of Orion


00:27:45.679 --> 00:27:47.029
because the sword is hanging down from


00:27:47.039 --> 00:27:50.070
his belt that fuzzy patch is the amazing


00:27:50.080 --> 00:27:53.269
great nebula in Orion it's a huge star


00:27:53.279 --> 00:27:55.389
forming region about 1300 light years


00:27:55.399 --> 00:27:56.990
from Earth you've probably seen pictures


00:27:57.000 --> 00:27:58.870
of it and if you haven't just get on the


00:27:58.880 --> 00:28:00.190
internet and just see plenty of pictures


00:28:00.200 --> 00:28:01.430
of it and Hubble and that sort of thing


00:28:01.440 --> 00:28:02.990
it looks looks amazing just see it with


00:28:03.000 --> 00:28:04.509
your own eyes if you just want to see


00:28:04.519 --> 00:28:06.630
this great neon with your own eyes go


00:28:06.640 --> 00:28:09.509
outside and let your eyes dark adapt for


00:28:09.519 --> 00:28:11.590
about 20 minutes or so that means just


00:28:11.600 --> 00:28:13.350
keep away from all sources of life don't


00:28:13.360 --> 00:28:14.470
look at lights because soon as you look


00:28:14.480 --> 00:28:15.990
at lights you blind yourself again when


00:28:16.000 --> 00:28:17.389
you're doing stargazing you've got to


00:28:17.399 --> 00:28:19.029
let your eyes adapt to the dark just


00:28:19.039 --> 00:28:21.230
keep away from lights street lights any


00:28:21.240 --> 00:28:22.509
lights on the outside of your house or


00:28:22.519 --> 00:28:23.909
the neighbor's house whatever try and


00:28:23.919 --> 00:28:25.269
get into somewhere shadowed where you


00:28:25.279 --> 00:28:26.509
just don't have any lights in then


00:28:26.519 --> 00:28:27.710
you'll be able to see the faint stuff


00:28:27.720 --> 00:28:29.909
because theion nebula is faint and it's


00:28:29.919 --> 00:28:32.190
small and fuzzy so get out there once


00:28:32.200 --> 00:28:33.470
your eyes are dark adapted and see if


00:28:33.480 --> 00:28:34.990
you can see this nebula it'll just be


00:28:35.000 --> 00:28:36.750
the tiniest smudge of light and you


00:28:36.760 --> 00:28:38.509
might have to use what's called averted


00:28:38.519 --> 00:28:40.149
Vision astronomers use this a lot


00:28:40.159 --> 00:28:41.470
averted Vision that's where you don't


00:28:41.480 --> 00:28:43.110
look directly at it but look at it sort


00:28:43.120 --> 00:28:45.070
of out the corner of your eye the sort


00:28:45.080 --> 00:28:46.669
of outside part of your or the outer


00:28:46.679 --> 00:28:48.149
part of your retina has the light


00:28:48.159 --> 00:28:50.310
receptors that respond very well to very


00:28:50.320 --> 00:28:52.269
dim objects they're good for nighttime


00:28:52.279 --> 00:28:53.870
stuff that you don't get color out of


00:28:53.880 --> 00:28:55.149
them you just get black and white but


00:28:55.159 --> 00:28:57.029
they are more sensitive to very faint


00:28:57.039 --> 00:28:58.669
light Lev so give that a right and even


00:28:58.679 --> 00:29:01.190
though it seems small and Tiny and fuzzy


00:29:01.200 --> 00:29:02.950
without using a telescope it is actually


00:29:02.960 --> 00:29:04.870
amazing to think that we can actually


00:29:04.880 --> 00:29:07.310
see this huge nebula 1300 light years


00:29:07.320 --> 00:29:09.230
away with just their eyes if you compare


00:29:09.240 --> 00:29:11.190
what you see with your eyes and then


00:29:11.200 --> 00:29:13.029
look at a picture of it you think wow


00:29:13.039 --> 00:29:14.669
that is amazing that I can see that and


00:29:14.679 --> 00:29:15.990
if you got a pair of binoculars that'll


00:29:16.000 --> 00:29:17.710
give you an even better View and even a


00:29:17.720 --> 00:29:19.950
small telescope will provide an amazing


00:29:19.960 --> 00:29:21.470
view so give that a try if you've got a


00:29:21.480 --> 00:29:23.110
small telescope or if you know someone


00:29:23.120 --> 00:29:25.190
who has you can borrow it or or go over


00:29:25.200 --> 00:29:27.070
and use it with them also visible in the


00:29:27.080 --> 00:29:28.269
northern part of the sky if you're


00:29:28.279 --> 00:29:29.830
looking from the mid latitudes in the


00:29:29.840 --> 00:29:31.110
Southern Hemisphere or it's in the


00:29:31.120 --> 00:29:32.350
southern part of the sky if you're


00:29:32.360 --> 00:29:34.029
looking from corresponding latitudes in


00:29:34.039 --> 00:29:35.269
the northern hemisphere there are a


00:29:35.279 --> 00:29:36.990
bunch of constellations of the zodiac


00:29:37.000 --> 00:29:38.269
around at the moment I mean there always


00:29:38.279 --> 00:29:39.549
are but these ones are really good ones


00:29:39.559 --> 00:29:41.590
they've got Taurus we've got Gemini


00:29:41.600 --> 00:29:43.710
Cancer and Leo Cancer and Leo they do


00:29:43.720 --> 00:29:46.230
seem a bit bare for uned the naked eye


00:29:46.240 --> 00:29:48.350
Stargazer not using a telescope but


00:29:48.360 --> 00:29:49.870
Gemini and Taurus are really good


00:29:49.880 --> 00:29:51.710
actually you can easily spot Gemini


00:29:51.720 --> 00:29:53.830
because it has two Bright Stars Castor


00:29:53.840 --> 00:29:56.389
and Pollock Gemini is the so-called


00:29:56.399 --> 00:29:58.509
constellation of the Twins and Castor


00:29:58.519 --> 00:30:00.029
and poock are these two bright stars


00:30:00.039 --> 00:30:01.549
that are fairly close to each other and


00:30:01.559 --> 00:30:03.029
they're fairly close in brightness to


00:30:03.039 --> 00:30:04.549
each other as well they're almost the


00:30:04.559 --> 00:30:06.269
same brightness so they are the twin


00:30:06.279 --> 00:30:08.710
stars of Gemini Taurus has a very


00:30:08.720 --> 00:30:11.590
recognizable wedge shaped group of stars


00:30:11.600 --> 00:30:13.669
I clust to call the hiades it's very


00:30:13.679 --> 00:30:15.710
easy to see and on on one edge of it


00:30:15.720 --> 00:30:17.710
there's a bright reddish star called Al


00:30:17.720 --> 00:30:19.509
Deon which is which is quite easy to


00:30:19.519 --> 00:30:21.149
spot as well there's another star


00:30:21.159 --> 00:30:23.110
cluster in Taurus it's called the


00:30:23.120 --> 00:30:24.909
pleades or the Seven Sisters which we've


00:30:24.919 --> 00:30:26.669
spoken about many times on the program


00:30:26.679 --> 00:30:28.590
and you can see this with the uned eye


00:30:28.600 --> 00:30:29.990
you'll probably only see six of the


00:30:30.000 --> 00:30:31.630
Stars though and you do need to give


00:30:31.640 --> 00:30:33.310
yourself that dark adaption time and


00:30:33.320 --> 00:30:34.830
also you might need to use the atic


00:30:34.840 --> 00:30:36.190
vision depending on how good your eyes


00:30:36.200 --> 00:30:38.070
up young people's eyes they're really


00:30:38.080 --> 00:30:39.830
good older people like me you know you


00:30:39.840 --> 00:30:41.590
need a bit of help so get yourself dark


00:30:41.600 --> 00:30:43.110
adapted and use a verted vision if you


00:30:43.120 --> 00:30:45.269
need to Now High overhead at this time


00:30:45.279 --> 00:30:46.669
of year for those of us in the south at


00:30:46.679 --> 00:30:48.470
least are the two brightest stars in the


00:30:48.480 --> 00:30:51.190
night sky that's Sirius and canopus


00:30:51.200 --> 00:30:52.750
Sirius the brighter of the two is


00:30:52.760 --> 00:30:54.430
actually a double star system you can't


00:30:54.440 --> 00:30:56.149
see the second of its Stars it's a tiny


00:30:56.159 --> 00:30:58.110
white dwarf in fact no one can see it so


00:30:58.120 --> 00:30:59.190
don't worry about that but it is a


00:30:59.200 --> 00:31:00.990
double star system the larger of its two


00:31:01.000 --> 00:31:02.830
stars the one we see it's twice as


00:31:02.840 --> 00:31:04.789
massive as the sun and yet although


00:31:04.799 --> 00:31:07.789
Sirius appears around twice as bright as


00:31:07.799 --> 00:31:09.269
that other star canopus the second


00:31:09.279 --> 00:31:11.509
brightest star kopus actually is


00:31:11.519 --> 00:31:14.029
intrinsically much brighter than Sirus


00:31:14.039 --> 00:31:15.830
it just seems dimmer than Sirius because


00:31:15.840 --> 00:31:17.669
it's a lot further away canopus is about


00:31:17.679 --> 00:31:19.789
310 light years from Earth whereas


00:31:19.799 --> 00:31:22.350
Sirius the intrinsically dimmer star is


00:31:22.360 --> 00:31:25.070
only 8.6 light years so it's quite


00:31:25.080 --> 00:31:26.990
nearby in space ter that's why it seems


00:31:27.000 --> 00:31:29.029
brighter than the ual brighter star


00:31:29.039 --> 00:31:31.029
canopus but they're both beautiful stars


00:31:31.039 --> 00:31:32.990
they're great uh you really can't miss


00:31:33.000 --> 00:31:34.789
them you know they are big and bright


00:31:34.799 --> 00:31:36.950
now going south along the Noy way past


00:31:36.960 --> 00:31:38.909
syrius in canopis heading down the South


00:31:38.919 --> 00:31:40.190
now we come to the far shn


00:31:40.200 --> 00:31:42.149
constellations such as ring cross and


00:31:42.159 --> 00:31:44.990
Karina theing cross is lying on its left


00:31:45.000 --> 00:31:47.149
hand side at the moment in mid evening


00:31:47.159 --> 00:31:49.830
during March but if you're awake around


00:31:49.840 --> 00:31:52.230
2:00 or 3:00 in the morning if you're


00:31:52.240 --> 00:31:54.070
stargazing then you'll find it much


00:31:54.080 --> 00:31:55.669
higher in the sky and then standing


00:31:55.679 --> 00:31:57.149
straight up that other constellation I


00:31:57.159 --> 00:31:59.830
mentioned Korean it has another big


00:31:59.840 --> 00:32:01.789
nebula that you can see with the uned


00:32:01.799 --> 00:32:03.830
eye like the IR nebula but this one is


00:32:03.840 --> 00:32:06.029
big it is really really big get out


00:32:06.039 --> 00:32:07.430
after midnight if you can when there are


00:32:07.440 --> 00:32:09.110
fewer lights around let yourself get


00:32:09.120 --> 00:32:11.350
dark adapted and you will see the Kina


00:32:11.360 --> 00:32:13.750
nebula with the uned eye it's enormous


00:32:13.760 --> 00:32:15.190
and then if you get a full philoscope


00:32:15.200 --> 00:32:16.909
onto it you can just spend hours sort of


00:32:16.919 --> 00:32:19.070
sweeping around this huge region of


00:32:19.080 --> 00:32:21.669
nebulosity out there in space it's it's


00:32:21.679 --> 00:32:23.509
it's it is everyone Rises about the


00:32:23.519 --> 00:32:25.950
greater IR nebula but really I think the


00:32:25.960 --> 00:32:27.590
great nebula in Kina is probably the


00:32:27.600 --> 00:32:29.549
better of the two certainly fascinating


00:32:29.559 --> 00:32:31.830
when you think of the ticking Time Bomb


00:32:31.840 --> 00:32:34.509
inside the nebulosity the two stars


00:32:34.519 --> 00:32:36.509
there that are both big blue super


00:32:36.519 --> 00:32:39.110
giants that are about to explode they


00:32:39.120 --> 00:32:40.629
are when we say about to explode of


00:32:40.639 --> 00:32:41.990
course we mean we don't mean like


00:32:42.000 --> 00:32:43.389
tomorrow or the next week or whatever or


00:32:43.399 --> 00:32:46.750
that suppose could be it could happen


00:32:46.760 --> 00:32:49.070
but likely of course it's going to be a


00:32:49.080 --> 00:32:51.029
long time from now but yeah in space


00:32:51.039 --> 00:32:52.590
astronomical terms and in spellar


00:32:52.600 --> 00:32:55.029
evolution terms yeah they're on the way


00:32:55.039 --> 00:32:58.070
out and any day now in terms of of you


00:32:58.080 --> 00:33:00.110
know the eons they're going to go bang


00:33:00.120 --> 00:33:01.789
that'll be pretty impressive they'll be


00:33:01.799 --> 00:33:04.190
bright enough to be seen in daylight


00:33:04.200 --> 00:33:05.509
probably as bright as the Moon is in


00:33:05.519 --> 00:33:07.430
daylight yeah yeah that would be really


00:33:07.440 --> 00:33:09.590
impressive I mean night time would be


00:33:09.600 --> 00:33:11.509
almost daytime it' be really really


00:33:11.519 --> 00:33:12.629
bright you wouldn't have any trouble


00:33:12.639 --> 00:33:14.269
reading a book outside that's for sure


00:33:14.279 --> 00:33:15.710
you probably have to wear sunglasses in


00:33:15.720 --> 00:33:17.590
fact Ste it now turning to the planets


00:33:17.600 --> 00:33:19.549
we've got Venus it's brief Venus is


00:33:19.559 --> 00:33:21.350
briefly visible right at the start of


00:33:21.360 --> 00:33:23.389
March but it's very low down on the


00:33:23.399 --> 00:33:25.750
western Horizon after sunset uh and it's


00:33:25.760 --> 00:33:27.470
soon going to disappear from view it's


00:33:27.480 --> 00:33:29.190
heading as we share from our line of


00:33:29.200 --> 00:33:30.430
side it's heading closer and closer to


00:33:30.440 --> 00:33:31.950
the sun it's not actually getting closer


00:33:31.960 --> 00:33:33.750
to the Sun but it's in line of sight


00:33:33.760 --> 00:33:35.310
Wise It's just getting closer so we're


00:33:35.320 --> 00:33:37.629
going to lose Venus very quickly for all


00:33:37.639 --> 00:33:39.950
of March basically it will reappear in


00:33:39.960 --> 00:33:41.509
the morning Sky just above the Eastern


00:33:41.519 --> 00:33:43.909
Horizon Before Sunrise early next month


00:33:43.919 --> 00:33:45.389
so if you want to see Venus next month


00:33:45.399 --> 00:33:47.430
onwards is is a better time Jupiter and


00:33:47.440 --> 00:33:48.990
Mars are very prominent in the evening


00:33:49.000 --> 00:33:51.110
Sky after sunset at the moment Jupiter


00:33:51.120 --> 00:33:52.470
can be found very close to that star


00:33:52.480 --> 00:33:54.149
cluster I mentioned earlier the high 8s


00:33:54.159 --> 00:33:56.590
in Taurus and also the the star Al de


00:33:56.600 --> 00:33:58.590
one it's it's close to those too big and


00:33:58.600 --> 00:33:59.990
bright and white and you really can't


00:34:00.000 --> 00:34:02.470
miss it Mars which is somewhat dimmer


00:34:02.480 --> 00:34:04.389
and has a sort of a ruddy orangey sort


00:34:04.399 --> 00:34:06.070
of color it can be found not far from


00:34:06.080 --> 00:34:07.629
those two stars in Gemini actually


00:34:07.639 --> 00:34:09.349
Castor and Pollock in fact it makes a


00:34:09.359 --> 00:34:11.510
nice triangle with them you got pretty


00:34:11.520 --> 00:34:13.109
much almost a nu colateral triangle now


00:34:13.119 --> 00:34:14.389
that I sort of picture it in my mind


00:34:14.399 --> 00:34:15.589
from the style map I was looking at


00:34:15.599 --> 00:34:17.669
earlier today you got Castor on poock as


00:34:17.679 --> 00:34:19.750
one base of a triangle and then at Apex


00:34:19.760 --> 00:34:21.869
you've got Mars so that should be pretty


00:34:21.879 --> 00:34:23.869
easy to spot as well finally Saturn


00:34:23.879 --> 00:34:25.270
unfortunately is pretty much out of view


00:34:25.280 --> 00:34:26.629
this month it's too close to the Sun


00:34:26.639 --> 00:34:28.190
from viewing the any time you're going


00:34:28.200 --> 00:34:30.149
to see it is in the last days of March


00:34:30.159 --> 00:34:31.869
just above the Eastern Horizon Before


00:34:31.879 --> 00:34:33.750
Sunrise but next month will be a lot


00:34:33.760 --> 00:34:35.950
better for that for those who get up


00:34:35.960 --> 00:34:37.790
before the dawn and that's St it is the


00:34:37.800 --> 00:34:39.629
skyer March that's science writer


00:34:39.639 --> 00:34:44.290
Jonathan NY and this is


00:34:44.300 --> 00:34:56.630
[Music]


00:34:56.640 --> 00:34:59.710
spacetime and that's the show for now


00:34:59.720 --> 00:35:01.630
SpaceTime is available every Monday


00:35:01.640 --> 00:35:03.430
Wednesday and Friday through Apple


00:35:03.440 --> 00:35:06.790
podcasts iTunes Stitcher Google podcast


00:35:06.800 --> 00:35:10.589
pocketcasts Spotify acast Amazon music


00:35:10.599 --> 00:35:11.870
bites.com


00:35:11.880 --> 00:35:14.670
SoundCloud YouTube your favorite podcast


00:35:14.680 --> 00:35:16.950
download provider and from SpaceTime


00:35:16.960 --> 00:35:20.150
with Stewart gar.com SpaceTime is also


00:35:20.160 --> 00:35:21.790
broadcast through the National Science


00:35:21.800 --> 00:35:24.270
Foundation on science Z Radio and on


00:35:24.280 --> 00:35:27.390
both iHeart radio and TuneIn radio and


00:35:27.400 --> 00:35:29.270
you can help to support our show by


00:35:29.280 --> 00:35:31.390
visiting the SpaceTime store for a range


00:35:31.400 --> 00:35:33.990
of promotional merchandising goodies or


00:35:34.000 --> 00:35:36.150
by becoming A Spacetime Patron which


00:35:36.160 --> 00:35:37.870
gives you access to Triple episode


00:35:37.880 --> 00:35:39.950
commercial free versions of the show as


00:35:39.960 --> 00:35:41.829
well as lots of bonus audio content


00:35:41.839 --> 00:35:43.870
which doesn't go to a access to our


00:35:43.880 --> 00:35:46.109
exclusive Facebook group and other


00:35:46.119 --> 00:35:48.310
Awards just go to SpaceTime withth


00:35:48.320 --> 00:35:51.750
Stewart gary.com for full details you've


00:35:51.760 --> 00:35:53.710
been listening to SpaceTime with Stuart


00:35:53.720 --> 00:35:56.190
Gary this has been another quality


00:35:56.200 --> 00:36:00.280
podcast production from fights.com