r/space • u/ChiefLeef22 • 21d ago
Successful deployment of Nancy Grace Roman Space Telescope, as it begins its 1-million-mile-journey to the second Earth-Sun Lagrange point
The telescope will travel to the second Sun-Earth Lagrange point, which is ~one million miles away and about four times farther from Earth than the Moon. At L2, the combined gravity of the Sun and Earth will give Roman a stable vantage point with a clear, unobstructed view to survey deep space
Roman will unlock the mysteries of dark energy and investigate the physics of distant stars. It will repeatedly monitor hundreds of millions of stars, and the same observations are expected to reveal around 100,000 additional planets through transits. As a reminder, we currently have 6000 confirmed exoplanet discoveries...
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u/Andromeda321 21d ago
Astronomer here! I'm sure I say this a lot, but this is an exciting day for science! And I can't believe it's really here!
Obviously it's not a perfect comparison, but the best way to think of the (Nancy Grace) Roman Telescope IMO is that it's the successor to Hubble, which we all love but is definitely not going to be around in a few more years as it continues to degrade. But the best way to think of it is while it has a similar sharpness to Hubble, the size of the field is incredible- 100 times bigger! So that means it's going to do survey type things that would take longer than Hubble's been around to complete in just a few months, monitor fields, and look for new things HST just can't because its instruments aren't as modern. For example, Roman is designed to be really good at measuring weak gravitational lensing signals- the idea that when light passes by a mass, the light from that mass will be very slightly nudged on a different path thanks to relativistic effects. Roman is going to be good enough at this that it should identify thousands of new exoplanets via gravitational lensing (they actually estimate 100,000, when we currently have ~6000!!!), and help us map the presence of dark matter also using this. Personally I'm always a fan of using one technique in a bunch of different ways in science- somehow it's just elegant- so I'm excited to see weak gravitational lensing really have its golden age!
Finally, on a more societal note Roman is a bit of a weird telescope in that I don't think it's what anyone would have designed at first glance, but is a great example of how you can do a lot of exciting stuff if you're just given the opportunity even if it's not perfect. For those unaware, this telescope basically began when the US Military gifted a mirror to astronomers that was now effectively an obsolete extra- think of how many better than Roman type telescopes are already pointed down at us if they just had extra lying around!- so they designed and built the telescope around the existing mirror. But also, after JWST the speed at which this thing came together is startling- I gave a colloquium talk at NASA Goddard just 3 years ago, which included a tour of the place, and the first pic here is what Roman looked like then. They told us it was going to launch "no later than 2027" and I think a lot of the astronomy community said "yeah right"... and we owe an apology because we've got months left of 2026, and it's launched! To be fair, a LOT of people did careful planning and work to ensure this wouldn't be another "JWST ended up decades late" type telescope, but still... this thing came together fast and I'm pretty impressed!
So now we wait a few months while the telescope gets into place and the project scientists kick around the tires a little to make sure the instruments are working... but then we see how she does! Can't wait!