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Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 4 points5 points  (0 children)

How tiny would a planet/asteroid be where its transit would be rendered undetectable by TESS?

It's a complicated answer, but a great question! Because the transit depth depends on the area ratio between the planet and star (Rp/R*)2, and the precision of the data depends on the brightness of the star, and the signal-to-noise also depends on the number of transits observed, the smallest size planet we can detect is different for every star. In general, we do better for planets on short orbits around small, bright stars. Taken to the extreme, we have actually detected a disintegrating minor planet around a white dwarf star (https://arxiv.org/abs/1510.06387).

Most planets detected by TESS will be Earth-sized or larger. See these papers for details: https://arxiv.org/pdf/1506.03845.pdf https://arxiv.org/abs/1804.05050

Will there be any great published photos of exoplanet transits?

We won't have images (TESS isn't an imaging mission, but a photometry mission), but I sure do expect a lot of beautiful published transit light curves! You can also expect the artists to get their work in creating artists' impressions to accompany exciting new planet discoveries. :)

-SQ

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 5 points6 points  (0 children)

I don't accept anything of the sort!

There are 100s of BILLIONS of stars in the Milky Way. We know, based upon data from Kepler and from other studies, that there is approximately 1 planet per star. So, the odds that none of these are Earth-like would have to be -- wait for it -- astronomical. I personally think that it's quite likely that there are a number of Earth-like planets out there -- the hard part is identifying them.

As for alien life? I just don't know. Again, just from the sheer numbers, it seems likely that some sort of life is out there -- and again, the hard part is identifying it. And, will alien life be intelligent alien life? Perhaps not....

As for percentage -- we've found a few thousand out of a potentially few hundred billion. So, 0.000001% or so. That might be off by a factor of a few.

-- SR

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 2 points3 points  (0 children)

The TESS orbit is stable for decades and the spacecraft consumes very little fuel per year, so TESS could remain operational for a long time! Our downlink rate is 10Mbit/s. The Ricker et al paper is a good place to start on the in-depth details! Link here: https://www.spiedigitallibrary.org/journals/Journal-of-Astronomical-Telescopes-Instruments-and-Systems/volume-1/issue-01/014003/Transiting-Exoplanet-Survey-Satellite/10.1117/1.JATIS.1.1.014003.full?SSO=1&tab=ArticleLink -NG

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 0 points1 point  (0 children)

TESS will be able to find planets the size of Earth around the nearest, brightest stars, and could detect passing asteroids in the data. TESS, like Kepler, only collects star light, so we will have lots of signatures we call light curves, which shows how a star's brightness decreases in light when a planet crosses in front of it. It can't actually photograph any planet however, that is for future missions!! -EQ

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 0 points1 point  (0 children)

One (of many!) expected result is: Humanity will learn how common terrestrial planets are in the habitable zone. By terrestrial I mean similar mass and size as the Earth. With this, we will be one big step closer to understanding how likely it is that life has evolved elsewhere in the Galaxy. D.D.

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 1 point2 points  (0 children)

There are lots of scientists interested in developing a citizen science program with TESS, many that helped develop those for Kepler/K2, so stay tuned!! TESS is going to collect SO much data, so it's going to be really fun to see what surprises we find with TESS.

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 2 points3 points  (0 children)

It is easier to put a satellite in orbit around Earth compared to L2. So whenever we don't need L2, we just use Earth orbit. JWST needs L2 because it needs to be very cold in order to get precise data in the infrared. TESS observes in the optical, and can stay in orbit around Earth (rather than go all the way to L2) because it doesn't need to be quite as cold. D.D.

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 1 point2 points  (0 children)

Well, the goal of TESS is really to put together a catalog of potential exoplanets that we'll be studying for a long time to come. As we find those objects (the TESS Objects of Interest, or TOIs), people will do follow-up observations from ground-based telescopes, and space-based telescopes like Hubble and JWST. Those will give us more information on these distant worlds, and we'll begin to understand how they compare to the planets in our own solar system.

It would be awesome to some day actually send some sort of probe out to newly discovered exoplanets, but I don't think we're technologically there just yet!

-- SR

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 1 point2 points  (0 children)

The TESS data will be a rich resource for follow-up of exoplanets as well as many other astrophysical phenomena. The TESS Follow-Up Operations Program (or TFOP) is always looking for interested observers and perhaps a citizen science project in data analysis for TESS in the works! -NG

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 4 points5 points  (0 children)

Hello, my favorite nearby star is Wolf 359, it's about 8 light years away and is a wildly flaring M dwarf. The Kepler telescope, K2, observed this star for 80 days late last year, and we have fantastic data for that star. We searched for transiting planets and didn't find any, but it's really hard to find planets around stars that flare so much. It could still have small planets that don't transit, which of course TESS wouldn't be able to detect. It's a fun system to study because of it's place in Star Trek history. Even if we don't find planets, the data from TESS can help us learn a lot about star flares and the environments of these tiny M dwarfs, which are the most abundant stars (>70%) in our galaxy. We also know that M dwarfs typically have 2 or more planets, so by learning about stars like this, it will help us understand other M dwarfs that do have planets (like TRAPPIST1). Thanks for the fun question :) -EQ

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 2 points3 points  (0 children)

The first TESS data release will be six months after the start of sector 1 on the Mikulski Archive for Space Telescopes here: https://archive.stsci.edu/tess/ -NG

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 0 points1 point  (0 children)

TESS is different than Hubble and James Webb. The individual cameras/telescopes are much smaller, but they are being used in a wide-field survey -- neither Hubble or Webb are designed for that. So, TESS is, in some sense, less powerful than either Hubble or Webb, but it can do something that neither of them can do!

-- SR

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 5 points6 points  (0 children)

Will TESS be doing anything to survey the current weird light fading phenomena occuring close to Tabby's Star (KIC 8462852)?

TESS is an all sky survey, so it will observe the Kepler field during the second year of its mission. I think the Kepler field falls in a region of sky that will be observed for two TESS sectors (~2 months). While it's possible that KIC 8462852 will show us something interesting in its photometric variation during that time, it often does very little. A ground-based campaign led by Professor Boyajian has been doing a very good job monitoring the system already! See the blog posts here.

It's probably more likely that insight will come from TESS observing other stars exhibiting phenomena like that seen around KIC 8462852, which could give us additional clues about the nature of the variability of KIC 8462852. If it's truly a rare system, then the all-sky nature of TESS should help find more of them.

-SQ

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 3 points4 points  (0 children)

An answer to question 2: The center of the TESS continuous viewing zone will overlap with the JWST continuous viewing zone. In this region of the sky as well as in other parts of James Webb's field-of-regard, we will find strong candidate exoplanets for follow-up observation after TESS, especially planets in the size range between Earth and Neptune. -NG

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 2 points3 points  (0 children)

Regarding CHEOPS: it has a much smaller field of view than TESS, such that it can only observe one star at a time. However, it is larger and will be able to see transits more precisely. So TESS will find thousands of planets, and CHEOPS will be able to observe in more detail the most interesting of the planets that TESS will find. D.D.

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 4 points5 points  (0 children)

There's a lot of detail there that I'm not going to go into here -- but there are papers on the subject! Each of the four TESS cameras have seven glass lenses. Focus was set in the lab using shims, and optical aberrations were carefully measured (these were minimized by design) so that they can be accounted for in data processing. Single exposures are 2 s, but they're co-added on board the space craft to the 2-minute and 30-minute cadence data that gets set to the ground. And yup, cosmic rays are a potential issue, but we can remove most of those with careful data processing.

-- SR

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 3 points4 points  (0 children)

Hello! With TESS, we don't get visual photos, we get starlight and we measure starlight for a long time for many many stars. It's truly amazing how scientists have been able to find planets just with starlight and clever data analysis techniques. In our quest to find other Earths, we have been taking one step at a time. Kepler found that other Earth-size planets exist in the habitable zone of other stars. Kepler only measured their size and orbits. TESS will use the same technique as Kepler, so will also measure the planet size and orbit, but will confirm planets around the nearest and brightest stars. We can then use all of our telescopes here on Earth to then point to those TESS stars that we know have planets, and measure their masses. With size and mass, you can calculate a planet's density. This allows us to see if we can find another planet that is rocky like Earth. But just because we find a rocky, Earth-sized planet in the habitable zone does't mean the planet is habitable! That is why NASA is building new missions, like James Webb Space Telescope, because we need to learn more about these planets. Webb will be able to probe the atmospheres of these planets and learn about their chemical makeup, and see if they could have atmospheres similar to ours here on Earth. -EQ

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 2 points3 points  (0 children)

I'll add -- I've worked with a number of graduate students at Goddard, and almost all of them have actually been non-US citizens! If you're a grad student and you're at a U.S. university, it's really easy -- if you can find a NASA scientist with whom to do a project (which isn't that big of a challenge). If you're at a canadian university, I think it's still possible -- it's really about making contact with a NASA scientist you want to work with.

-- SR

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 1 point2 points  (0 children)

TESS will find transiting planets, like other surveys have done before it (Kepler, and a few ground-based surveys). But these other surveys either only found planets (of all sizes) around distant faint stars, or around nearby bright stars but only large planets. TESS will find small planets around nearby bright stars. That means that we can then observe those planets with other telescopes in more detail (measure their masses and observe their atmospheres), because they will be much closer to us than most of the small planets found so far. D.D.

Science AMA Series: We’re NASA, MIT and Kepler scientists excited about the launch of our newest planet hunter, TESS. AMA! by NASAGoddard in science

[–]NASAGoddard[S] 3 points4 points  (0 children)

Hello, Goddard here. We do have international internships - however these are with specific countries that have agreements with NASA. You can find them here. https://ossi.nasa.gov/non-us-opportunities/index.html However, as Diana mentioned, there are many more opportunities for post-graduate work with NASA. If you plan to continue your education this might be your best path. - Karl