Is there life beyond Earth? A question so imperative that it has powered numerous sci-fi genres as well as historic missions like NASA’s Kepler Spacecraft. The implications of that question being answered will change the course of humanity forever.
Currently, we have 2,237 confirmed planets. Meaning we have identified that many planets exist with actual observations that lie beyond our solar system. Of course, we estimate there to be at least 100 billion in our own galaxy, but observing them with our own eyes is a different story.
Enter the new age of hunting for exoplanets. NASA’s Transiting Exoplanet Survey Satellite or (TESS) will usher in a new set of fresh eyes for us. Let’s take a look at what TESS is, how it’ll find these planets, and why it’s an incredibly exciting mission that will launch in 2017-2018.
How does TESS work?
Exoplanet hunters, like NASA’s Kepler Space Telescope, look for planets by observing their shadow. It’s called the transit photometry technique. How does that work? Let me show you:
Credit: http://www.astronomynotes.com/
What’s happening here is the planet goes around its parent star and on the light spectrum (the rainbow spectrum shown on the right hand side), shows a dip or a wobble. This indicates to the observer that there is an object in the way. Now there are some disadvantages to this technique but currently this is one of the best and successful techniques used to date.
Here’s a better animation of the same thing happening here to help reinforce this technique:
Credit: https://lostintransits.wordpress.com/
This exact method has helped Kepler spacecraft confirm 2,327 exoplanets today.
TESS Missions Specifications:
Now that we know how TESS will be looking for these exoplanets let’s take a look at the spacecraft specs as well as the mission specs in greater detail. This is what really impressed me!
TESS Science Objectives¹:
- Monitor 50,000 nearby stars for planets
- Focus on Earth and Super-Earth size planets
- Cover 400x larger sky than Kepler
Transiting exoplanets allow us to observe the following for those planets that transit nearby bright stars:
- Fundamental properties: mass, radius, orbit
- Dynamics: planet-planet interactions, mutual inclinations, moons, tides
- Atmospheric composition + structure: transmission, spectrum, emission spectrum, albedo, phase function, clouds, winds
TESS Mission Overview:
All-sky, two year photometric exoplanet discovery mission
TESS will tile the sky with 26 observation sectors:
- At least 27 days staring at each 24° x 96° sector
- Brightest 100,000 stars at 1-minute cadence
- Full frame images with 30-minute cadence
- Map Northern hemisphere in first year
- Map Southern hemisphere in second year
TESS Science Instrument:
Four wide field-of-view CCD cameras
Each of the four cameras has:
- 24° x 24° Field-of-View
- 100 mm effective pupil diameter
- Lens assembly with 7 optical elements
- Athermal design
- 600nm – 1000nm bandpass
- 16.8 megapixel, low-noise, low-power, MIT Lincoln lab CCID-80 detector
TESS Spacecraft:
Designed for photometric stability
Heritage Orbital LEOStar-2 spacecraft bus:
- 3-axis stabilized pointing, with ≤3 arc-sec performance
- Two-headed star tracker, 4 wheel zero-momentum system
- 400W single-axis articulating solar array
- Passive thermal control
- Mono-propellant propulsion system
- Ka-band 100 Mbps science downlink
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