Roman Opens Its Eye

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Anna: On Friday, a camera the size of a small car

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finished cooling to minus

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143 degrees Celsius,

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a million and a half kilometres from here.

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Over the weekend, NASA turned it on and

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then it looked at a star.

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Avery: The picture is blurry, deliberately,

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gloriously blurry. And it is the most

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important image the Nancy Grace Roman Space

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Telescope will ever take.

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Anna: Welcome to Astronomy AstroDailyPod. I'm Anna.

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Avery: And I'm avery. It's Wednesday 16th

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September 2026. Coming to you from

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Sydney.

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Anna: Coming up, Roman opens its eye and

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finds it has twice as long to look as anyone

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planned.

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Avery: Caltech says the solar system has an

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expiry date and it is very much earlier

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than the textbooks say.

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Anna: The United States says out loud. And for the

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first time that it has weapons in orbit,

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Rubin finds a

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Avery: globular cluster that was hiding behind a

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hundred thousand light years of dust and bad

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luck.

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Anna: Starship finally has a date and a Venus

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that is about to be as bright as it gets.

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Avery: Let's get into it.

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Anna: Let's start with a telescope we have been

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following all the way from the launch pad. On

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30 August, we watched the Nancy Grace

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Roman Space Telescope leave Kennedy on a

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Falcon Heavy. On 1st September, its

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Coronagraph Instrument got its first taste of

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electrical power. And this week, the main

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event, Roman's primary instrument, is awake

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and it has seen starlight.

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Avery: This is the wide field instrument.

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Anna: It is, and it's worth being precise about

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what it actually is because the specification

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is doing something unusual. It's a 300

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megapixel infrared camera built around 18

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separate detectors. Its field of view is at

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least a hundred times larger than Hubble's

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infrared field. The practical way to say that

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is in a single exposure.

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Roman captures a patch of sky bigger than the

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full moon at a sharpness comparable to

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Hubble's. Hubble takes exquisite postage

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stamps. Roman takes exquisite murals.

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Avery: And the activation happened over about four

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days.

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Anna: It did, and NASA has walked through it step

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by step, which I appreciate. On Friday the

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11th, the instrument finished cooling to its

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operating temperature. Minus

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225 Fahrenheit, minus

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143 Celsius. Infrared

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detectors have to be cold because if they

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aren't, the camera sees its own heat instead

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of the sky. Then across the 11th and

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12th, the team brought up all 18 infrared

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detectors and the calibration system. On

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the 12th, the element wheel, the carousel

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that swings filters and optical elements into

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the light path, turned in microgravity for

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the first time.

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On the 13th, they confirmed the Focus

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mechanism moves the way it's supposed to.

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Avery: Any one of which could have gone

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Anna: wrong, any one of which could have ended the

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mission. Frankly, a stuck filter wheel

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on an instrument a million and a half

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kilometres away is not a thing. You send

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somebody up to jiggle and then they pointed

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it at stars and took the picture I mentioned

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at the top, which is out of focus and

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which is exactly right.

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Avery: Explain that. Because our new

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billion dollar telescope took a blurry photo

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is a headline waiting to be misread?

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Anna: It is. So let's head it off. You do

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not focus an instrument before you know the

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detectors work. The order of operations is

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prove the detectors respond, prove they

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respond uniformly, establish a baseline

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and only then start the long fussy business

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of focusing a telescope that has been shaken

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by a rocket and then allowed to settle in

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vacuum. Those defocused stars

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smeared across thousands of pixels are a

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diagnostic. They tell you the optical path

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is clear, every detector is live, and

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the light is arriving where the model said it

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would. Josh Schlieder, the wide field

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instrument scientist at Goddard, put it

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plainly. After years of effort building and

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testing the instrument on the ground, they

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now have confirmation that it is operational

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in space.

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Sharp science images are expected by early

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2027 and the coronagraph

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progressing. The team at Caltech and IPAC

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have completed initial communications,

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testing software, thermal systems,

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mechanisms, cameras, avionics, all, all

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responding. It's now sitting through 30 day

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decontamination cycles at room temperature

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about 22 degrees to bake off any

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contaminants before it gets cold and precise.

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That's the instrument we talked about on the

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6th, the technology demonstrator. That's

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meant to prove we can block a star's light

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well enough to photograph a planet beside it.

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Avery: Okay, but the thing that actually made me sit

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up this week wasn't the first light. It was

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the fuel.

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Anna: It's the better storey. And it landed the day

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before. On Monday the 14th, NASA

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published the numbers from Roman's first mid

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course correction. The burn that fine tunes

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the trajectory out to the second Lagrange

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point. That burn was better than 99%

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accurate. It used under 10% of what had

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been allocated to it. About 18 kilogrammes

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of propellant out of a, uh, 200 kilogramme

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budget.

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Avery: And accuracy converts directly into fuel.

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Anna: Directly. Every kilogramme you don't spend

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correcting an error is a kilogramme you can

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spend later holding station and pointing. On

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top of that, the spacecraft came in lighter

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than the maximum it was allowed to be. So it

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launched with margin. It was never supposed

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to have. Add the accurate first burn,

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add the launch margin, add what they expect

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from the second burn and the insertion into

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orbit around L2. And Jamie Dunn at

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Goddard says the quiet part out loud.

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Roman has fuel for at least 22 years of

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potential science operations against a

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design life of 10 five years primary,

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five years extended. So this is roughly

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double. And here is where I want to be

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careful because NASA telescope's life

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doubled is going to be everywhere this week

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and it needs a caveat attached.

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22 years is a fuel figure, it is not a

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funding figure and it is not a hardware

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figure. Detectors degrade, budgets get

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written annually. Fuel is one of several

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things that can end a space telescope and

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Roman has just removed it from the top of the

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list. That's genuinely excellent news.

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It is not a promise of 22 years of science.

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Avery: Understood. So why does the fuel matter

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so much for this particular telescope?

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Anna: Because of what Roman was built to measure

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and because of what we led with on Monday.

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Remember Monday's lead the Australian

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led supernova compilation out of the

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University of Queensland with ANU and

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Swinburne2884

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type Ia supernovae Pantheon

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and the full dark energy survey five year

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sample rebuilt in one framework and a

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2.5 to 3.1-sigma preference for

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dark energy that changes over time rather

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than staying constant.

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Avery: Which was tantalising and not conclusive.

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Anna: Exactly that. And the reason it wasn't

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conclusive is the reason Roman exists. You

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are trying to detect a slow drift in a number

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and your enemies are sample size and

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systematics. Dust host

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galaxy properties, the slow accumulation

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of small calibration differences between

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surveys. Roman attacks all three

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Its high latitude Time domain survey about

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six months of observing Hunt's Type Ia

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supernovae specifically to measure how the

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expansion rate has changed. Its high

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latitude Wide area survey about 17 months

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covers more than 5,000 square degrees to

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probe the origin of cosmic acceleration

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through weak gravitational lensing and galaxy

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clustering. A completely independent handle

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on the same question.

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Avery: Two different methods, one telescope, one

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calibration.

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Anna: Which is the whole point. Monday's paper was

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heroic precisely because it had to stitch

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together three decades of different

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instruments.

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Roman gets to skip that problem and now it

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gets to do it for 22 years instead of 10.

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Which is not just more supernovae. It's a

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longer lever arm in time. And in this

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measurement the lever arm is everything.

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Avery: There's the exoplanet half too.

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Anna: There is, and it's extraordinary. The

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Galactic bulge time domain survey 15 months

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or so, 6 observing seasons imaging the

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crowded heart of the Galaxy every 12 minutes,

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12.1 minutes, to be exact. That

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Cadence is designed to catch gravitational

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microlensing events, and it's expected to

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find more than a thousand planets on wide

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orbits, the cold, distant worlds that transit

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surveys are almost blind to, plus something

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like a hundred thousand transiting planets as

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a bonus.

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Avery: And for southern listeners, there's a thread

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running through all of this.

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Anna: There is, and it's the one I keep coming back

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to.

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The Dark Energy survey data in Monday's paper

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came off the Blanco 4 metre telescope at

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Cerro Tololo in Chile. The

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compilation was led out of Brisbane. The

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accelerating universe result that started

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this whole argument was work Brian Schmidt

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did at Matt Stromlo outside Canberra.

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The question about dark energy got sharpened

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in the Southern sky over 30 years by

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people working in our half of the world. And

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this week the instrument built to settle it

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opened its eye, took a deliberately blurry

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picture of a star and found out it has twice

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as long to look as anyone had planned.

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Avery: Not a bad week.

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Anna: Not a bad week at all.

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Avery: Right, let's talk about how the solar system

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ends, because three people at Caltech have

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just moved the date forward by about a

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billion fold.

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Anna: That is an aggressive revision.

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Avery: It really is. The paper is by

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Constantine Batygin, Jim Fuller and

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Fred Watson Adams. It went up on the archive

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on Friday the 11th, and it's been accepted by

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the Astrophysical Journal Letters. So it's

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five days old and peer reviewed, but not yet

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in the Journal. I'll flag that as we go.

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The title is Terminal Instability of the

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Solar System Triggered by Stochastic Solar

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Mass Loss.

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Anna: Give me the old number first.

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Avery: 10 to the 18 years. A billion

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billion years. That's the standard estimate

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for how long the giant planets Jupiter,

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Saturn, Uranus, Neptune hold

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their current orbital architecture together.

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And it already accounts for the sun losing

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mass as it dies, and for the occasional

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passing star. It is an absurdly long

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time. The universe is 14 billion

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years old.

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Anna: So what breaks it?

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Avery: An assumption nobody was really examining.

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That the sun sheds its mass smoothly.

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That as it becomes a red giant and then a

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white dwarf, it releases material steadily

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and symmetrically, like a tyre with a slow

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puncture, and the planet's orbits widen

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gently in response.

267
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Anna: And that isn't what happens.

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Avery: Apparently not. And the evidence comes from

269
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white dwarfs themselves. Measure how

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fast white dwarfs are moving and they show

271
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recoil. A kick. A kick means

272
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the mass didn't leave evenly. It left

273
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in discrete, independently directed

274
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ejections. Parcels, not a stream,

275
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each one shoving the star a different way,

276
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and the

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Anna: planets are attached to the star's gravity,

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so they feel every shove.

279
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Avery: That's the mechanism. The star jitters and

280
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the planet's orbits take a random walk in

281
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response, each ejection nudging them a little

282
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in no particular direction, with the size of

283
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the nudges set by how lumpy the mass loss

284
00:11:50.380 --> 00:11:53.100
is. Do that for long enough and

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orbits that were carefully spaced drift into

286
00:11:55.780 --> 00:11:58.540
each other's business. And once giant

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planets start perturbing each other in

288
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earnest, the outcome is scattering planets

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thrown onto wild orbits or thrown out

290
00:12:06.060 --> 00:12:06.780
altogether.

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Anna: What do the simulations give?

292
00:12:08.940 --> 00:12:11.540
Avery: About 40% of the modelled systems are

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disrupted or violently scattered because

294
00:12:14.110 --> 00:12:16.790
before the sun even finishes becoming a white

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dwarf, and roughly 90%

296
00:12:19.550 --> 00:12:22.230
come apart within about 3 billion years.

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After that, the headline number the

298
00:12:25.110 --> 00:12:27.870
dynamical lifetime of the outer solar system

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drops from 10 to the 18 years to

300
00:12:30.910 --> 00:12:33.910
somewhere around 1 billion years past white

301
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dwarf formation.

302
00:12:35.790 --> 00:12:38.470
Anna: I want to be clear, for anyone reaching for

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the panic button, please, none

304
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Avery: of this is near term anything. The

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sun has about 5 billion years of normal

306
00:12:46.790 --> 00:12:49.310
life left and Earth's surface becomes

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uninhabitable long before the interesting

308
00:12:51.990 --> 00:12:54.630
part of this paper begins. What it

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changes isn't a forecast, it's a

310
00:12:57.190 --> 00:12:58.830
prediction. We can go and cheque.

311
00:12:59.710 --> 00:13:01.950
Meaning, if this is right,

312
00:13:02.350 --> 00:13:05.350
planetary systems around old white dwarfs

313
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should be rarer, more scattered and more

314
00:13:08.190 --> 00:13:10.830
chaotic than the smooth mass loss picture

315
00:13:10.830 --> 00:13:13.420
predicts. We already find white

316
00:13:13.420 --> 00:13:16.020
dwarfs polluted with the debris of shredded

317
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rocky bodies, which tells us something

318
00:13:18.420 --> 00:13:21.260
violent happens out there. This gives

319
00:13:21.260 --> 00:13:23.940
that violence a mechanism and a rate.

320
00:13:24.580 --> 00:13:27.300
And the caveat, the honest one, is

321
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it's a simulation result. And the answer

322
00:13:30.660 --> 00:13:33.380
depends entirely on how granular the mass

323
00:13:33.380 --> 00:13:35.940
loss really is. Big

324
00:13:36.100 --> 00:13:38.740
infrequent parcels give you a very different

325
00:13:38.740 --> 00:13:41.350
system for from small frequent ones.

326
00:13:41.910 --> 00:13:44.670
That granularity is now the number to go and

327
00:13:44.670 --> 00:13:47.470
measure. Which is a nice place for a paper

328
00:13:47.470 --> 00:13:50.230
to end, not with a claim, but with an

329
00:13:50.230 --> 00:13:50.870
assignment.

330
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Anna: Now, a storey that isn't astronomy, but which

331
00:13:54.510 --> 00:13:56.870
sits directly over the sky, we all use.

332
00:13:57.510 --> 00:13:59.630
On Monday, at the opening of the Air and

333
00:13:59.630 --> 00:14:02.470
Space Forces Association's Air, Space and

334
00:14:02.470 --> 00:14:04.350
Cyber Conference at National Harbour in

335
00:14:04.350 --> 00:14:06.870
Maryland, the Secretary of the Air Force,

336
00:14:06.870 --> 00:14:09.710
Troy Meink, said that the United

337
00:14:09.790 --> 00:14:12.550
States now has, in his words, on

338
00:14:12.550 --> 00:14:15.110
orbit space control weapons capable of

339
00:14:15.110 --> 00:14:17.790
defending the joint force against hostile

340
00:14:17.790 --> 00:14:19.070
adversary actions.

341
00:14:19.630 --> 00:14:21.710
Avery: That's the first time that's been said out

342
00:14:21.710 --> 00:14:22.110
loud.

343
00:14:22.510 --> 00:14:24.870
Anna: It is the first public acknowledgment by the

344
00:14:24.870 --> 00:14:27.630
United States military that it has offensive

345
00:14:27.630 --> 00:14:30.470
capability in orbit. And I want to be

346
00:14:30.470 --> 00:14:32.670
precise about what was and wasn't said,

347
00:14:33.200 --> 00:14:35.840
because the gap matters. What was said?

348
00:14:36.240 --> 00:14:39.160
The capability exists, it is on orbit

349
00:14:39.160 --> 00:14:41.600
and it is framed as defensive of the Joint

350
00:14:41.600 --> 00:14:44.360
Force. What was not said, what the

351
00:14:44.360 --> 00:14:47.200
systems are, how many there are, where they

352
00:14:47.200 --> 00:14:49.880
are, when they got there, or what they can

353
00:14:49.880 --> 00:14:50.560
actually do.

354
00:14:51.120 --> 00:14:53.040
Avery: Did anyone define the term?

355
00:14:53.520 --> 00:14:55.720
Anna: A Space Force spokesperson did, and the

356
00:14:55.720 --> 00:14:58.320
definition is broad. Space control, they

357
00:14:58.320 --> 00:15:01.040
said, encapsulates the mission areas required

358
00:15:01.040 --> 00:15:03.280
to contest and control the space domain,

359
00:15:03.600 --> 00:15:06.040
employing kinetic and non kinetic means to

360
00:15:06.040 --> 00:15:08.240
affect adversary capabilities through

361
00:15:08.240 --> 00:15:11.120
disruption, degradation and if

362
00:15:11.120 --> 00:15:13.840
necessary, destruction. So that covers

363
00:15:13.840 --> 00:15:16.080
everything from M jamming a signal to

364
00:15:16.080 --> 00:15:18.600
physically destroying a satellite. And the

365
00:15:18.600 --> 00:15:20.480
statement doesn't tell us where on that

366
00:15:20.480 --> 00:15:22.000
spectrum these systems sit.

367
00:15:22.640 --> 00:15:23.760
Avery: Why say it now?

368
00:15:23.920 --> 00:15:26.660
Anna: That question got answered the following day.

369
00:15:26.900 --> 00:15:29.660
General Douglas Schies, the Chief of Space

370
00:15:29.660 --> 00:15:32.580
Operations, said on Tuesday, I think it

371
00:15:32.580 --> 00:15:34.820
was time that within the Department of War we

372
00:15:34.820 --> 00:15:37.220
talked about it and it's time to talk about

373
00:15:37.220 --> 00:15:39.500
that. We have the capabilities to make sure

374
00:15:39.500 --> 00:15:42.460
that we can do what the Joint Force needs. He

375
00:15:42.460 --> 00:15:44.780
attributed the decision to advances by China

376
00:15:44.780 --> 00:15:47.460
and Russia in anti satellite capability

377
00:15:47.700 --> 00:15:49.980
and said the United States needed to be able

378
00:15:49.980 --> 00:15:52.020
to respond from a position of strength.

379
00:15:52.910 --> 00:15:54.110
Avery: How is that being read?

380
00:15:54.670 --> 00:15:57.310
Anna: Two ways, and I think both are worth hearing.

381
00:15:57.790 --> 00:15:59.870
The deterrence reading is that capability.

382
00:16:00.110 --> 00:16:03.030
Nobody knows about deters. Nobody. That if

383
00:16:03.030 --> 00:16:05.430
the point of a weapon is to make an adversary

384
00:16:05.430 --> 00:16:08.430
decide not to act, the adversary has to

385
00:16:08.430 --> 00:16:11.350
know it exists on that reading. Saying it

386
00:16:11.350 --> 00:16:13.870
out loud is the whole function. The arms

387
00:16:13.870 --> 00:16:15.990
control reading is that public acknowledgment

388
00:16:15.990 --> 00:16:18.400
by the largest space power lowers the

389
00:16:18.400 --> 00:16:20.720
threshold for everyone else, invites

390
00:16:20.720 --> 00:16:23.480
reciprocal declarations and makes the orbital

391
00:16:23.480 --> 00:16:26.040
environment more contested rather than less,

392
00:16:26.440 --> 00:16:28.800
with debris as the physical consequence that

393
00:16:28.800 --> 00:16:30.600
outlives any particular dispute.

394
00:16:31.160 --> 00:16:33.400
Avery: And debris is where this touches us.

395
00:16:33.960 --> 00:16:36.880
Anna: That's the part I'd hold onto. We covered US

396
00:16:36.880 --> 00:16:39.160
Space Command's Apollo manoeuvres exercise

397
00:16:39.160 --> 00:16:41.680
last week. The first live fly orbital

398
00:16:41.680 --> 00:16:43.720
manoeuvre drill with allies including

399
00:16:43.800 --> 00:16:46.360
Australia, under Operation Olympic Defender.

400
00:16:46.870 --> 00:16:48.910
Australia has its own Defence Space Command

401
00:16:48.910 --> 00:16:51.110
and we're part of that framework. But

402
00:16:51.110 --> 00:16:53.830
whatever anybody's strategic view, kinetic

403
00:16:53.830 --> 00:16:56.390
action in low Earth orbit produces debris,

404
00:16:56.550 --> 00:16:59.510
and debris doesn't respect flags. Every

405
00:16:59.510 --> 00:17:02.070
fragment is a hazard to every satellite and

406
00:17:02.470 --> 00:17:05.070
in the long run, to the sky above every

407
00:17:05.070 --> 00:17:07.470
observatory on the ground. We'll keep

408
00:17:07.470 --> 00:17:09.910
reporting this one factually as it develops.

409
00:17:10.150 --> 00:17:12.150
The conference is still running as we record.

410
00:17:13.150 --> 00:17:15.230
Avery: Lets finish the news with something that made

411
00:17:15.230 --> 00:17:18.110
me grin. The Vera Rubin Observatory

412
00:17:18.110 --> 00:17:20.590
has found a globular cluster in our own

413
00:17:20.590 --> 00:17:23.310
galaxy that nobody had ever catalogued.

414
00:17:23.630 --> 00:17:26.590
Anna: In our own galaxy in 2026,

415
00:17:27.230 --> 00:17:27.510
in

416
00:17:27.510 --> 00:17:30.110
Avery: our own galaxy in 2026.

417
00:17:30.510 --> 00:17:33.150
The paper went up on Monday. Lead author

418
00:17:33.150 --> 00:17:35.710
Ashay Pai with William Cerny,

419
00:17:35.790 --> 00:17:38.790
Andrew Pace, Alex Drlica, Wagner and

420
00:17:38.790 --> 00:17:40.920
colleagues across Chicago, Yale,

421
00:17:41.080 --> 00:17:43.640
Dartmouth, Washington and Colorado.

422
00:17:43.800 --> 00:17:46.720
They've named it Rubin GC1. And they

423
00:17:46.720 --> 00:17:49.320
found it in Rubin's early data preview too.

424
00:17:49.720 --> 00:17:52.200
Not even the survey proper. The preview.

425
00:17:52.760 --> 00:17:53.880
Anna: Where was it hiding?

426
00:17:54.360 --> 00:17:57.280
Avery: In the worst possible direction, towards the

427
00:17:57.280 --> 00:17:59.760
galactic bulge. You're looking through the

428
00:17:59.760 --> 00:18:02.560
thickest dust in the galaxy at a field so

429
00:18:02.560 --> 00:18:04.960
crowded with foreground stars that a faint

430
00:18:04.960 --> 00:18:07.640
clump is statistically invisible. Trying to

431
00:18:07.640 --> 00:18:09.640
pick out something that isn't bright to begin

432
00:18:09.640 --> 00:18:09.920
with.

433
00:18:10.640 --> 00:18:12.000
Anna: So it's in the bulge?

434
00:18:12.720 --> 00:18:15.640
Avery: No. And this is the lovely bit. It's

435
00:18:15.640 --> 00:18:18.480
behind it. Rubin GC1 is

436
00:18:18.480 --> 00:18:21.360
about 31 kiloparsecs away. Call it

437
00:18:21.360 --> 00:18:24.120
a hundred thousand light years. That puts it

438
00:18:24.120 --> 00:18:26.760
out in the Milky Way's halo, seen through the

439
00:18:26.760 --> 00:18:29.520
bulge. A, uh, halo object sitting in the most

440
00:18:29.520 --> 00:18:31.360
confusing line of sight we have.

441
00:18:31.840 --> 00:18:32.880
Anna: What is it physically?

442
00:18:33.200 --> 00:18:36.000
Avery: Small and old, half light radius around

443
00:18:36.000 --> 00:18:38.700
5 parsecs. A compact little ball,

444
00:18:39.180 --> 00:18:42.140
absolute magnitude about minus 2.4,

445
00:18:42.300 --> 00:18:45.100
which is faint for a globular. The authors

446
00:18:45.100 --> 00:18:47.420
place it in the faint tail of the globular

447
00:18:47.420 --> 00:18:50.060
cluster. Luminosity function age

448
00:18:50.060 --> 00:18:52.300
about 9.2 billion years.

449
00:18:52.700 --> 00:18:54.220
Moderately metal poor.

450
00:18:54.860 --> 00:18:57.180
Anna: And where did it come from?

451
00:18:57.900 --> 00:19:00.900
Avery: This is my favourite part. They took Gaia's

452
00:19:00.900 --> 00:19:03.420
third day to release proper motions, measured

453
00:19:03.420 --> 00:19:05.420
how the cluster is actually moving through

454
00:19:05.420 --> 00:19:08.180
space and ran the phase space modelling

455
00:19:08.180 --> 00:19:10.860
backwards. The answer that comes out is that

456
00:19:10.860 --> 00:19:13.420
Rubin GC1 was very probably

457
00:19:13.420 --> 00:19:15.460
stripped from the Sagittarius dwarf

458
00:19:15.460 --> 00:19:17.940
spheroidal galaxy, one of the small

459
00:19:17.940 --> 00:19:20.580
galaxies the Milky Way is currently eating.

460
00:19:21.140 --> 00:19:23.060
So it isn't ours originally.

461
00:19:23.140 --> 00:19:25.420
Anna: It's spoils that needs

462
00:19:25.420 --> 00:19:26.900
spectroscopy to confirm.

463
00:19:26.900 --> 00:19:29.590
Avery: Presumably it does, and the

464
00:19:29.590 --> 00:19:32.190
authors say so. That's the next beat,

465
00:19:32.270 --> 00:19:34.150
along with the fact that this is early

466
00:19:34.150 --> 00:19:36.750
preview data, not the full survey.

467
00:19:36.990 --> 00:19:39.270
But step back, because there's a pattern

468
00:19:39.270 --> 00:19:41.630
here. We have now hit four times in a month.

469
00:19:42.030 --> 00:19:44.830
M M74 turned out to be more than twice

470
00:19:44.830 --> 00:19:47.550
its catalogue size. Magnetars

471
00:19:47.550 --> 00:19:50.110
turned out to be half of all neutron stars,

472
00:19:50.110 --> 00:19:53.030
rather than 1%. Mercury turned

473
00:19:53.030 --> 00:19:55.510
out to have shrunk up to 30% more than we

474
00:19:55.510 --> 00:19:58.400
thought. And now a globular cluster a

475
00:19:58.400 --> 00:20:00.800
hundred thousand light years away turns out

476
00:20:00.800 --> 00:20:02.920
to have been sitting in our catalogue's blind

477
00:20:02.920 --> 00:20:04.120
spot the whole time.

478
00:20:04.760 --> 00:20:07.360
Anna: Catalogues are detection limits, not

479
00:20:07.360 --> 00:20:08.120
censuses.

480
00:20:08.840 --> 00:20:11.480
Avery: That's the line and it keeps being true.

481
00:20:12.119 --> 00:20:14.520
This cluster wasn't missing because it's far

482
00:20:14.520 --> 00:20:17.480
away. Plenty of catalogued globulars are.

483
00:20:17.480 --> 00:20:20.000
Further, it was missing because it's faint

484
00:20:20.000 --> 00:20:22.610
and behind dust and, and in a crowded

485
00:20:22.610 --> 00:20:25.450
direction. Three handicaps stacked on

486
00:20:25.450 --> 00:20:28.250
each other. Ruben removed enough of the first

487
00:20:28.250 --> 00:20:29.650
to overcome the other two.

488
00:20:30.210 --> 00:20:32.890
Anna: And Ruben is on Cerro Pachon in

489
00:20:32.890 --> 00:20:35.330
Avery: Chile in our half of the sky.

490
00:20:35.730 --> 00:20:37.990
And two names on that author list are, uh,

491
00:20:38.050 --> 00:20:40.970
old friends of this programme. Nora Shipp

492
00:20:40.970 --> 00:20:43.330
was on the Stellar Streams paper we led with

493
00:20:43.330 --> 00:20:46.210
on the 7th. Alex Drelika Wagner

494
00:20:46.210 --> 00:20:48.910
is a dark energy survey scientist. Which

495
00:20:48.910 --> 00:20:50.430
ties straight back to Monday.

496
00:20:51.070 --> 00:20:53.550
Same small community, same southern

497
00:20:53.550 --> 00:20:55.950
telescopes. Three different questions.

498
00:20:56.510 --> 00:20:59.310
Anna: We've ended three recent leads with wait for

499
00:20:59.310 --> 00:20:59.870
Rubin.

500
00:21:00.430 --> 00:21:03.390
Avery: Stellar Streams, the Trans Neptunian Objects

501
00:21:03.390 --> 00:21:05.470
and Monday's dark energy result.

502
00:21:06.110 --> 00:21:08.750
This is the first instalment on that promise

503
00:21:08.750 --> 00:21:10.910
and it came out of a data preview.

504
00:21:11.470 --> 00:21:13.550
Rubin hasn't really started yet.

505
00:21:14.360 --> 00:21:16.640
Anna: Next up, a quick hit. And it's an update to

506
00:21:16.640 --> 00:21:18.600
something we left unresolved Yesterday.

507
00:21:19.160 --> 00:21:21.640
Starship Flight 14 has a firm date.

508
00:21:22.280 --> 00:21:24.200
Finally, finally.

509
00:21:24.440 --> 00:21:26.360
Yesterday we had to carry two dates and a

510
00:21:26.360 --> 00:21:28.840
caveat. An FAA advisory showing the

511
00:21:28.840 --> 00:21:31.400
18th reporting pointing to the 22nd

512
00:21:31.800 --> 00:21:33.800
and no formal word from SpaceX.

513
00:21:34.440 --> 00:21:36.960
SpaceX has now published and the FAA has

514
00:21:36.960 --> 00:21:39.960
cleared it. Tuesday the 22nd of September.

515
00:21:40.430 --> 00:21:43.340
Uh, a 75 minute window opening at 8:15 in the

516
00:21:43.340 --> 00:21:46.100
morning Eastern. That's 12:15 UTC

517
00:21:46.420 --> 00:21:48.940
and 10 past 10 in the evening Sydney time on

518
00:21:48.940 --> 00:21:49.620
the 22nd.

519
00:21:49.940 --> 00:21:51.860
Avery: And um, this is the orbital one.

520
00:21:52.260 --> 00:21:55.260
Anna: This is the orbital one six orbits at about

521
00:21:55.260 --> 00:21:58.140
275 kilometres then

522
00:21:58.140 --> 00:22:00.580
splash down in the Pacific west of Chile

523
00:22:01.060 --> 00:22:03.940
roughly 10 hours after launch. So this flight

524
00:22:03.940 --> 00:22:06.590
ends in our half of the world. The payload is

525
00:22:06.590 --> 00:22:09.590
26 Starlink V3 satellites, the

526
00:22:09.590 --> 00:22:11.190
first flight of the next generation

527
00:22:11.190 --> 00:22:13.070
satellites designed specifically for

528
00:22:13.070 --> 00:22:13.710
starship.

529
00:22:14.110 --> 00:22:16.470
And three of them carry cameras to photograph

530
00:22:16.470 --> 00:22:18.430
the ship's heat shield during re entry.

531
00:22:18.910 --> 00:22:21.790
Booster Gulf splashdown about seven

532
00:22:21.790 --> 00:22:24.510
minutes after liftoff. And confirming what we

533
00:22:24.510 --> 00:22:27.470
corrected on air back on the 12th. No tower

534
00:22:27.470 --> 00:22:29.550
catches on this flight for either stage.

535
00:22:30.110 --> 00:22:32.790
SpaceX's framing is that going to orbit is

536
00:22:32.790 --> 00:22:34.350
what unlocks the next phase.

537
00:22:35.020 --> 00:22:37.220
Their line is that by going to orbit, the

538
00:22:37.220 --> 00:22:39.620
work of making starship fully and rapidly

539
00:22:39.620 --> 00:22:40.860
reusable can begin.

540
00:22:41.340 --> 00:22:44.220
Avery: And that brings us to the sky. And this is

541
00:22:44.220 --> 00:22:45.340
a good week in it.

542
00:22:45.660 --> 00:22:47.940
Anna: Start with tonight, because tonight is lovely

543
00:22:47.940 --> 00:22:50.659
and it's free. Go out at dusk and find the

544
00:22:50.659 --> 00:22:53.580
moon, a waxing crescent about a quarter lit,

545
00:22:53.580 --> 00:22:56.140
five days old. Sitting right beside it is

546
00:22:56.140 --> 00:22:58.700
Antares, the red heart of Scorpius.

547
00:22:59.100 --> 00:23:02.050
How close from Sydney? Two and a half

548
00:23:02.050 --> 00:23:04.690
degrees apart at nautical dusk and both of

549
00:23:04.690 --> 00:23:07.570
them about 60 degrees up. A pairing you can

550
00:23:07.570 --> 00:23:09.450
cover with two fingers at arm's length.

551
00:23:09.610 --> 00:23:12.250
Sitting high overhead From Los Angeles,

552
00:23:12.490 --> 00:23:14.810
five and a half degrees apart and 18 degrees

553
00:23:14.810 --> 00:23:17.690
up. From New York, nearly seven degrees

554
00:23:17.690 --> 00:23:19.290
apart and 12 degrees up.

555
00:23:19.770 --> 00:23:22.410
Avery: Same sky, wildly different view.

556
00:23:23.050 --> 00:23:25.730
Anna: Same sky, same night. And it's the

557
00:23:25.730 --> 00:23:27.610
ecliptic tilt we talked about yesterday.

558
00:23:28.290 --> 00:23:30.450
Around the September equinox, the ecliptic

559
00:23:30.450 --> 00:23:32.610
stands up almost vertically from the western

560
00:23:32.610 --> 00:23:34.770
horizon at dusk in the southern hemisphere

561
00:23:34.930 --> 00:23:37.650
and lies down almost flat in the northern.

562
00:23:38.210 --> 00:23:40.450
Everything on that line, the Moon,

563
00:23:40.690 --> 00:23:43.530
Venus. Mercury rides high and

564
00:23:43.530 --> 00:23:46.410
lingers in the south and hugs the horizon in

565
00:23:46.410 --> 00:23:49.210
the north. In March, it reverses and

566
00:23:49.210 --> 00:23:50.770
the north gets the good version.

567
00:23:51.170 --> 00:23:52.850
Avery: Which brings us to Venus.

568
00:23:52.930 --> 00:23:55.460
Anna: And, um, Friday, Friday the 18th,

569
00:23:55.620 --> 00:23:58.620
Venus reaches greatest brilliancy, about

570
00:23:58.620 --> 00:24:01.580
magnitude -4.8, the brightest it

571
00:24:01.580 --> 00:24:04.140
gets in this evening apparition. And the

572
00:24:04.140 --> 00:24:05.980
reason is worth understanding because it's

573
00:24:05.980 --> 00:24:08.940
counterintuitive. Venus is not brightest when

574
00:24:08.940 --> 00:24:09.700
it's fullest.

575
00:24:10.180 --> 00:24:10.820
Avery: Go on.

576
00:24:11.380 --> 00:24:13.620
Anna: Right now, Venus is a Crescent, only about

577
00:24:13.620 --> 00:24:16.580
26% lit, but it's swinging in towards

578
00:24:16.580 --> 00:24:19.540
us. So its disc has swollen to about 39

579
00:24:19.540 --> 00:24:22.150
arcseconds across. Enormous as

580
00:24:22.150 --> 00:24:25.030
planets go. Brightness depends on the total

581
00:24:25.030 --> 00:24:27.990
illuminated area, which is the lit fraction

582
00:24:27.990 --> 00:24:30.990
multiplied by the size of the disc. As Venus

583
00:24:30.990 --> 00:24:33.590
approaches, the crescent thins, but the disc

584
00:24:33.590 --> 00:24:36.150
grows. And the product of those two peaks,

585
00:24:36.150 --> 00:24:39.110
right about now, a thin crescent that's very

586
00:24:39.110 --> 00:24:41.750
big beats a full disc that's very small.

587
00:24:42.390 --> 00:24:45.190
Avery: And at, uh, 39 arcseconds, you can actually

588
00:24:45.350 --> 00:24:46.390
see the crescent.

589
00:24:46.390 --> 00:24:49.080
Anna: You, you can steady a pair of binoculars

590
00:24:49.080 --> 00:24:51.760
against a fence post or a wall, and Venus

591
00:24:51.760 --> 00:24:54.080
resolves into a crescent rather than a dot.

592
00:24:54.560 --> 00:24:56.760
That's a genuinely startling thing to show

593
00:24:56.760 --> 00:24:59.600
somebody who has never looked where and when

594
00:25:00.080 --> 00:25:02.640
west after sunset. And the two hemispheres

595
00:25:02.640 --> 00:25:05.400
get very different deals. From Sydney, Venus

596
00:25:05.400 --> 00:25:08.200
stands nearly 40 degree high at sunset and

597
00:25:08.200 --> 00:25:10.120
sets about three and a quarter hours after

598
00:25:10.120 --> 00:25:13.050
the sun. You cannot miss it. From Los

599
00:25:13.050 --> 00:25:15.210
Angeles, it sets about an hour and 20 minutes

600
00:25:15.210 --> 00:25:17.490
after the sun. From New York, about an hour

601
00:25:17.490 --> 00:25:19.730
and five. So for, uh, our North American

602
00:25:19.730 --> 00:25:22.290
listeners, and you are our largest audience,

603
00:25:22.770 --> 00:25:25.650
the honest advice is look low in the west

604
00:25:25.890 --> 00:25:28.890
20 to 45 minutes after sunset with a clear

605
00:25:28.890 --> 00:25:31.250
horizon, it's bright enough to punch through

606
00:25:31.250 --> 00:25:33.570
twilight. You just need to be looking at the

607
00:25:33.570 --> 00:25:35.810
right time without a building in the way.

608
00:25:36.290 --> 00:25:38.690
Avery: There's a southern only bonus this week, too.

609
00:25:39.420 --> 00:25:41.180
Anna: Mercury magnitude

610
00:25:41.180 --> 00:25:44.180
-0.4, which is bright, but only

611
00:25:44.180 --> 00:25:46.460
16 degrees from the sun, which is awful.

612
00:25:47.180 --> 00:25:49.660
From Sydney, the steep ecliptic rescues it

613
00:25:49.980 --> 00:25:52.700
15 degrees up at sunset, setting more than an

614
00:25:52.700 --> 00:25:55.540
hour after the Sun. From London, it's three

615
00:25:55.540 --> 00:25:58.340
degrees up and effectively unobservable same

616
00:25:58.340 --> 00:26:01.220
planet, same brightness. A real target in

617
00:26:01.220 --> 00:26:02.940
the south and a non event in the north.

618
00:26:03.660 --> 00:26:04.300
Avery: Saturn.

619
00:26:04.820 --> 00:26:07.580
Anna: Saturn is everybody's. It rises about an hour

620
00:26:07.580 --> 00:26:10.020
and a quarter after sunset from Sydney and

621
00:26:10.020 --> 00:26:12.740
under an hour after sunset from New York, Los

622
00:26:12.740 --> 00:26:15.300
Angeles and London. So from anywhere it's

623
00:26:15.300 --> 00:26:17.420
well placed by full dark and stays up all

624
00:26:17.420 --> 00:26:20.180
night. Magnitude around 0.3

625
00:26:20.660 --> 00:26:23.500
disc just under 20 arc seconds. Rings about

626
00:26:23.500 --> 00:26:26.220
7 degrees open heading for opposition on the

627
00:26:26.220 --> 00:26:27.140
4th of October.

628
00:26:27.780 --> 00:26:29.660
If you have a telescope, this is

629
00:26:29.660 --> 00:26:32.100
Avery: the month moon phase for the weekend.

630
00:26:32.500 --> 00:26:34.780
Anna: First quarter on Friday the 18th at

631
00:26:34.780 --> 00:26:37.580
2043 UTC, which is

632
00:26:37.580 --> 00:26:40.260
Saturday morning 27 in Sydney.

633
00:26:40.580 --> 00:26:43.020
And that timing is not an accident because

634
00:26:43.020 --> 00:26:45.500
Saturday the 19th is international observe

635
00:26:45.500 --> 00:26:47.900
the Moon, uh, night. NASA is running public

636
00:26:47.900 --> 00:26:50.620
events and observatories and astronomy clubs

637
00:26:50.620 --> 00:26:51.940
around the world will be too.

638
00:26:52.500 --> 00:26:54.260
Avery: Why first quarter specifically?

639
00:26:54.820 --> 00:26:57.140
Anna: Because a full moon is the worst moon.

640
00:26:57.740 --> 00:26:59.860
At full the sunlight comes straight down and

641
00:26:59.860 --> 00:27:02.620
everything looks flat and washed out. At

642
00:27:02.620 --> 00:27:05.180
first quarter, the terminator, the line

643
00:27:05.180 --> 00:27:08.060
between lit and unlit runs down the middle of

644
00:27:08.060 --> 00:27:10.820
the disc and along that line the sun is low

645
00:27:10.820 --> 00:27:13.299
and every crater rim and mountain throws a

646
00:27:13.299 --> 00:27:15.980
long black shadow. The Moon looks three

647
00:27:15.980 --> 00:27:16.620
dimensional.

648
00:27:17.020 --> 00:27:19.100
That's what you want to show somebody. And

649
00:27:19.100 --> 00:27:21.500
that's why the date moves each year to land

650
00:27:21.500 --> 00:27:22.380
near first quarter.

651
00:27:23.110 --> 00:27:25.470
Avery: And the pre dawn sky belongs to the north.

652
00:27:25.470 --> 00:27:28.070
Anna: This week it does. And that's a fair trade

653
00:27:28.070 --> 00:27:30.990
for Venus. Mars and Jupiter are both in the

654
00:27:30.990 --> 00:27:33.950
east before sunrise. From Los Angeles

655
00:27:33.950 --> 00:27:36.910
and New York, Mars is 45 to 47

656
00:27:36.910 --> 00:27:39.470
degrees up at nautical dawn with

657
00:27:39.470 --> 00:27:41.830
Jupiter about 24 degrees below it.

658
00:27:42.230 --> 00:27:44.470
A comfortable civilised pairing.

659
00:27:45.110 --> 00:27:47.630
From Sydney, Mars is 20 degrees up and

660
00:27:47.630 --> 00:27:50.610
Jupiter is a struggle at 8. Jupiter

661
00:27:50.610 --> 00:27:52.970
is the bright one at minus 1.7.

662
00:27:53.610 --> 00:27:56.370
Mars the modest orange dot at plus

663
00:27:56.370 --> 00:27:58.970
1.2. And they're closing

664
00:27:59.370 --> 00:28:02.370
24 degrees apart this morning, about 12

665
00:28:02.370 --> 00:28:05.170
by mid October and just 2 degrees apart by

666
00:28:05.170 --> 00:28:07.490
the middle of November. Put that in your

667
00:28:07.490 --> 00:28:09.930
calendar now, zodiacal light

668
00:28:10.490 --> 00:28:12.930
standing item. And the Moon is out of the way

669
00:28:12.930 --> 00:28:15.740
again after the 26th. For from the southern

670
00:28:15.740 --> 00:28:17.940
hemisphere it's a faint cone in the west

671
00:28:17.940 --> 00:28:19.060
after full dark.

672
00:28:19.220 --> 00:28:22.180
The false dusk from the northern hemisphere

673
00:28:22.180 --> 00:28:24.580
it's the same cone in the east before dawn,

674
00:28:24.740 --> 00:28:27.700
the false dawn, same dust, same

675
00:28:27.700 --> 00:28:30.540
tilt. Opposite ends of the night running

676
00:28:30.540 --> 00:28:33.140
through to early November. You need a dark

677
00:28:33.140 --> 00:28:34.100
sight and patience.

678
00:28:34.820 --> 00:28:37.300
Avery: And um, the equinox next Wednesday.

679
00:28:37.860 --> 00:28:39.580
Anna: And this is the clarification we made

680
00:28:39.580 --> 00:28:41.800
yesterday, and I wanna keep making the

681
00:28:41.800 --> 00:28:44.800
September equinox is a single instant five

682
00:28:44.800 --> 00:28:47.440
minutes past midnight UTC on the 23rd,

683
00:28:47.840 --> 00:28:49.800
which means it falls on the evening of the

684
00:28:49.800 --> 00:28:52.680
22nd across the Americas and mid morning

685
00:28:52.680 --> 00:28:54.000
on the 23rd in Australia.

686
00:28:54.800 --> 00:28:57.280
An equinox is a moment, not a day,

687
00:28:57.760 --> 00:29:00.040
and which calendar date it lands on depends

688
00:29:00.040 --> 00:29:01.680
entirely on where you're standing

689
00:29:02.320 --> 00:29:05.120
Avery: and the safety line, which we never cut.

690
00:29:05.760 --> 00:29:08.250
Anna: Never. But with Venus this bright, some of

691
00:29:08.250 --> 00:29:09.890
you will want to try to find it in broad

692
00:29:09.890 --> 00:29:12.650
daylight. And you can. It's genuinely doable,

693
00:29:13.130 --> 00:29:16.130
but you must do it safely. Do not sweep the

694
00:29:16.130 --> 00:29:18.530
daytime sky with binoculars or a telescope.

695
00:29:18.530 --> 00:29:21.410
Hunting for Venus One accidental pass

696
00:29:21.410 --> 00:29:24.050
across the sun at that magnification and the

697
00:29:24.050 --> 00:29:26.490
damage to your eye is instant and permanent.

698
00:29:26.890 --> 00:29:29.450
Use a building or a wall to physically block

699
00:29:29.450 --> 00:29:31.370
the sun from your field of view before you

700
00:29:31.370 --> 00:29:33.810
start and know where Venus is before you

701
00:29:33.810 --> 00:29:36.380
look. And if you have any eclipse glasses

702
00:29:36.380 --> 00:29:38.740
left over from August, those are for looking

703
00:29:38.740 --> 00:29:39.620
at the sun only.

704
00:29:39.940 --> 00:29:41.060
They must carry the

705
00:29:41.060 --> 00:29:43.140
ISO12312

706
00:29:44.180 --> 00:29:47.060
certification and they must be undamaged.

707
00:29:47.780 --> 00:29:49.860
Never look at the sun through any optics

708
00:29:49.860 --> 00:29:52.300
without proper solar filtration fitted at the

709
00:29:52.300 --> 00:29:54.660
front. Your eyes do not grow back.

710
00:29:55.220 --> 00:29:57.220
Avery: That's Astronomy daily for Wednesday

711
00:29:57.300 --> 00:29:58.900
16th September.

712
00:29:59.300 --> 00:30:02.060
Anna: Roman's wide field instrument is alive. It it

713
00:30:02.060 --> 00:30:04.660
has seen its first starlight and it has fuel

714
00:30:04.660 --> 00:30:07.260
for 22 years instead of 10, which

715
00:30:07.260 --> 00:30:09.580
matters most for the dark energy question an

716
00:30:09.580 --> 00:30:11.620
Australian LED team sharpened on Monday.

717
00:30:12.100 --> 00:30:15.060
Avery: Caltech has cut the solar system's dynamical

718
00:30:15.060 --> 00:30:17.660
lifetime from a billion billion years to

719
00:30:17.660 --> 00:30:20.580
about a billion by pointing out that dying

720
00:30:20.580 --> 00:30:22.260
stars don't lose mass.

721
00:30:22.260 --> 00:30:24.980
Anna: Politely, the United States has said out

722
00:30:24.980 --> 00:30:27.660
loud for the first time that it has weapons

723
00:30:27.660 --> 00:30:28.340
in orbit.

724
00:30:28.710 --> 00:30:31.270
Avery: Rubin has found a globular cluster a hundred

725
00:30:31.270 --> 00:30:33.590
thousand light years away that was hiding

726
00:30:33.590 --> 00:30:36.070
behind dust crowding and its own

727
00:30:36.070 --> 00:30:38.310
faintness. From a data preview

728
00:30:39.030 --> 00:30:40.110
Starship flies on

729
00:30:40.110 --> 00:30:42.990
Anna: the 22nd and Venus is at its brightest

730
00:30:42.990 --> 00:30:43.590
on Friday.

731
00:30:44.470 --> 00:30:47.190
Avery: Show notes, sources and links for every

732
00:30:47.190 --> 00:30:50.070
storey are at astronomydaily IO

733
00:30:50.310 --> 00:30:53.110
and there's a contact form there. We read

734
00:30:53.110 --> 00:30:55.140
everything that comes through it, and

735
00:30:55.140 --> 00:30:57.460
listener questions have driven segments on

736
00:30:57.460 --> 00:30:59.100
this programme more than once.

737
00:30:59.980 --> 00:31:02.620
Anna: You'll find us as astrodaily pod on Social

738
00:31:02.700 --> 00:31:04.500
and Astronomy AstroDailyPod wherever you get

739
00:31:04.500 --> 00:31:07.300
your podcasts. If the show is useful to you,

740
00:31:07.300 --> 00:31:09.340
the single most helpful thing you can do is

741
00:31:09.340 --> 00:31:11.100
tell one other person about it.

742
00:31:11.660 --> 00:31:12.700
Avery: I'm Avery.

743
00:31:13.020 --> 00:31:15.860
Anna: And I'm Anna. Astronomy AstroDailyPod is a

744
00:31:15.860 --> 00:31:18.460
production of the bytes.com podcast network

745
00:31:18.860 --> 00:31:21.260
clear Skies and if you're anywhere near the

746
00:31:21.260 --> 00:31:23.870
west after sunset this week or go and look at

747
00:31:23.870 --> 00:31:24.390
Venus

748
00:31:27.040 --> 00:31:27.880
Avery: mhm.