Here's Why GAIA Is My Absolute Favourite Space Telescope

Gaia data works its way into so much science. It really has made a foundational contribution to astronomy.

I use a free astronomy software called Cartes du Ciel. It uses no star catalogs other than GAIA DR3. I have nearly every star in the sky down to magnitude 21, with full astrometry on every star. Distance (parallax), spectral type, proper motion, radial velocity, and GAIA catalog number. No matter what telescope I use there's no star in my eyepiece that isn't in Cartes du Ciel with GAIA DR3. GAIA has constructed a 3D map of the Milky Way in motion to analyze star associations, origins and destinations. GAIA discovered that several billion years ago, the Milky Way ate a smaller galaxy called Gaia Enceladus, whose stars are different than native Milky Way stars, both in motion and chemistry. By coincidence our solar neighborhood is particularly dense in nearby Gaia Enceladus stars. The sun, however, and our solar system are native Milky Way.

Amazing! The more technical Dr Holl gets, the more amazing the engineering is revealed to be.

Thanks for this amazing interview! And greetings from the ESA Control Center in Darmstadt, Germany! I actually started watching the video from the room where Gaia is operated. A colleague just send me this video in the moment I was investing an issue with the Mission Control System… Anyways, in case you can’t get enough of Gaia - there is also a lot of interesting facts about operations of Gaia. Just two examples: To make a super-precise observation, you not only require crazy accuracy in both orbit and attitude - you also need perfect time stamping of your observations! Therefore Gaia even has an atomic clock onboard! Also, there is periods of time during which the Galactic Plane enters Gaia’s field of view. As Gaia is tracking every single bright object, it generates much more data than usual which can be more than 60gb per day! To downlink all this data we require 24/7 groundstation coverage to somehow get all data downlinked to Earth.

The animation of how the CCD collector works, showing how the precise rotation rate allows for the operation of the telescope, and why it can’t continue science operations without refueling was a particularly interesting part of the conversation.

One of the best episodes. It's obvious your interest in the topic. What made this episode is you let him talk and discuss. Very well done Fraser. This was, in my opinion opinion, your best interview.

I really appreciate that Dr. Berry Holl, got super technical. I wish he would have kept talking. I'm not an expert in this area, but it's super interesting to me.

He looks like the mystery character in an old Superman movie, who you think is going to be a villain, but then in Act III he saves the day

Berry was very informative! THANK YOU SO MUCH!

Hey Berry, great talk. I enjoyed it 😁

I love GAIA too.

Aloha. Yep. GAIA rules. It helps so many astronomers from all corners of their subject.

Thank you so much for this beautiful interview, it is so nice to hear two persons speak with so much passion about what they love. Dankjewel Dr. Berry Holl :elbowcough:

Dr holl is so interesting i hope that he will comeback for another itw soon

Summary: Mission Overview: - (0:00) Gaia is a space telescope mapping the Milky Way by observing the positions, motions, and properties of billions of stars. - (0:18) It provides a comprehensive 3D map used for diverse astronomical discoveries. How Gaia Works: - (6:49) Located at the L2 Lagrange point, Gaia orbits the Sun alongside Earth, avoiding obstruction by the Earth and Moon. - (7:07) It spins every six hours and uses two telescopes with a wide field of view, observing every part of the sky multiple times over its mission. - (7:53) The resulting data is sparsely sampled, creating challenges for analysis but providing rich information. Gaia's Capabilities: - (11:28) Astrometry: Gaia precisely measures star positions and distances using parallax, achieving unprecedented accuracy. - (13:00) Proper Motion: By observing stars over time, Gaia detects their movement across the sky. - (16:42) Radial Velocity: A spectrometer measures the stars' motion towards or away from us (redshift). - (18:49) Photometry and Spectroscopy: Two photometers provide data on star brightness and color, aiding in classification and rough chemical composition analysis. Limits of Gaia: - (22:28) Limited by its sensitivity, Gaia can only observe about 2 billion stars, representing 1% of the Milky Way. - (23:48) Although capable of detecting exoplanets, its sensitivity limits discovery to larger planets like Jupiter and above. - (40:41) Gaia's mission will end soon due to depleting thruster gas, expected in early 2024. What Comes Next: - (49:13) Gaia NIR: A proposed successor mission aims to perform similar observations in near-infrared wavelengths, enabling observations of stars hidden by dust and expanding the survey's reach. - (55:09) Other Potential Missions: Future possibilities include even more sensitive astrometry missions and space-based interferometry to directly image exoplanets. Surprising Discoveries: - (33:02) Gaia has enabled the measurement of the Solar System's acceleration around the galactic center. - (35:37) It has revealed stellar streams and groups, providing evidence of past mergers with the Milky Way. - (34:24) Gaia data contributed to mass estimates of the Milky Way based on the velocity of stars on escape trajectories. - (30:18) An unexpected discovery was the classification of many galaxies based on their variability as a function of Gaia's scanning angle. Overall Impact: - (38:25) Gaia has provided a wealth of data, democratizing astronomy by making it accessible to a wider range of researchers. - (37:52) It has led to a deeper understanding of the Milky Way's structure, evolution, and stellar populations. - (41:51) Gaia's legacy will continue to fuel astronomical discoveries for years to come. i used gemini 1.5 pro

Your interviews are great, Fraser and team. Thank you for your hard work.

That was great to also hear all these technical details, shows how much work goes into these missions to get out the best quality results. Just amazing

Gaia for president!

LOVE GAIA, Loved this interview! Thanks guys!

SPACE EXPLORATION LEADERBOARD The telescope laypeople know about: Hubble, and now JWST The telescope that gets mentioned in basically every astrophysics topic: GAIA The telescope which is the most under-rated: Chandra XRO The telescope which is the most hyped: JWST, and now Vera Rubin The telescope which has surpassed its original mission objective by the largest margin: Voyager 1, Hubble, or Opportunity depending how you measure it The shortest-lived telescope to collect groundbreaking data: Venera 7, Galileo Entry Probe, or Huygens I realize that I'm really stretching the definition of telescope at this point.