The Earth-based Rubin Observatory and Nancy Grace Roman Space Telescope launched this year, both figuratively and literally. The Rubin Observatory in Chile began observing on this past June and the Nancy Grace Roman Telescope was recently launched in August — headed to join JWST at the Sun-Earth Lagrange point, L2 — and is expected to begin observations this December. Each observatory has a unique and interesting mission, equipped with novel technologies that help to push the boundaries of astronomical research.
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Astro Brief is a podcast collaboration between KSMU, the Missouri Space Grant, and MSU's Department of Physics, Astronomy and Materials Science. Hosted by Dr. Mike Reed, Astro Brief focuses on astronomical events, the field of astronomy, and astronomy-related guests. It airs Thursdays at 9:45 am on KSMU.
Transcript
With the recent launch of the Nancy Grace Roman Space Telescope, we thought it might be a good idea to discuss recent observatories and their intended uses.
Let's begin with the Roman Space Telescope, named after Nancy Grace Roman — who is often described as the mother of the Hubble Space Telescope and NASA's first chief of astronomy. And that relation to HST is uncanny. Roman's 2.4 meter mirror was donated by the National Reconnaissance Office and is exactly the same size and used the same production facilities as HSTs. Yes, these are spy satellite mirrors, and Roman's will be the second one looking away from the Earth with a classified number of those mirrors looking at the Earth.
Originally, Roman was only going to have a 1.5 meter mirror, and so the donation was both a blessing — as larger mirrors see fainter objects — and a curse — as the telescope had to be redesigned for the larger mirror and the launch vehicle had to be changed. It was originally scheduled to launch on a Delta IV rocket, but instead needed SpaceX's Falcon Heavy. But the redesign did not delay Roman and in fact it launched roughly six months ahead of schedule.
As we record this, the telescope is healthy and heading towards its final destination at L2 where it will join JWST and ESA's Euclid Telescope.
This orbit is stationary compared to the Earth and like the Earth directly orbits the Sun. Because of the extra size, Roman will probe more and better than originally intended. Its wide field instrument has a view 100 times larger than Hubble's but with the same resolving power. This image will be split between eight different wavelength filters covering all the way from blue light to near infrared.
That is Roman's workhorse and it is expected to obtain about 1.4 terabytes of data per day on three major surveys.
The first is a survey looking out of the plane of our galaxy to measure dark energy, cosmic acceleration, and dark matter. It will do this by observing billions of galaxies and by determining how they are moving — what is moving them.
The second survey is also looking out of the galactic plane but will observe a bit more rapidly to search for supernova and other transient stuff. This survey will look at the sample places every five days.
The third survey is looking towards the densely crowded galactic center with the goal of detecting micro-lensing events. Such events are good for detecting exoplanets, faint stars and hidden black holes. Roman also has a coronagraph which basically is a spot that blocks light so Roman's detector can look for faint objects near bright ones. This is really a test instrument and it will be used to look at Jupiter sized exoplanets. It will guide the coronagraph design for upcoming Habitable Worlds Observatory which should launch in the 2040's and is hoping to look at Earth-like planets.
Roman should begin getting data in January and Rubin began its observing mission this past June so let's talk about that.
Back in March we did discuss Rubin a bit, but now it's actually operating. Named after Vera Rubin, who was one of the discoverers of dark matter, and it's named that because like Roman is going to map millions or even billions of galaxies which should help us understand dark matter and dark energy. Of course being on the Earth it can only see one hemisphere and in this case it's the southern hemisphere and there's always daytime and clouds and whatnot, so space telescopes have that advantage.
But Rubin's big advantage is that it's a big telescope with a huge camera on it.
It has a 3.4 billion pixel camera behind a 27 foot diameter light bucket and it's already collecting 10–20 terabytes of data per night. Rubin is also interested in transient events like supernova, gravitational lenses and moving solar system objects like asteroids, comets and potentially even finding our Planet Nine in the outer solar system.
This camera gets a new picture every 30 to 40 seconds and it's sending out about 10 million transient alerts per night. Really an astronomical number.
Most of those so far are supernova or variable stars like eclipsing binaries or pulsating stars like what I study. It shouldn't be long before observational papers will be published.
We should check in with JWST.
It's nominal five year mission ends next July. It is expected to work for at least 10 years beyond that and likely has enough fuel for another 15 years. All systems are working well and the quality of its data has surpassed what was actually expected. So far it has generated over 2,600 scientific papers. That's a great return on investment.
So there's lots of interesting observations either currently operating or that will be in the near future. Lots of fuel for Astro Brief episodes.