We recently reported on a transport of 2,200 new exoplanets from the main two-year mission of the Transiting Exoplanet Survey Satellite (TESS). But that’s just the tip of the iceberg in terms of exoplanet hunting. If NASA’s calculations are correct, the Nancy Grace Roman Space Telescope could detect up to 100,000 new exoplanets when launched in 2025.
There are two ways that Roman will search for potential exoplanets. The first is a more traditional method, already used by TESS and Kepler, of looking for a star’s faiting dimming that occurs when a planet passes in front of it. This technique, known as transit, is the process by which the majority of exoplanets have been found so far.
UT video of transits – one of the techniques Roman uses to discover new exoplanets.
Roman will have much more sensitive systems than any transit exoplanet satellite launched to date. This sensitivity enables it to see worlds that are much further away than TESS and similar satellites. Exoplanets found by TESS are generally about 150 light years away, while Kepler focused on a particular path in the sky that is up to about 2,000 light years away. While it’s nice to collect data on our galactic neighborhood, there are a relatively small number of stars there. Roman, on the other hand, will be sensitive enough to detect planetary candidates at a distance of up to 26,000 light years, which extends almost to the center of the galaxy.
But it won’t come to that with transit technology alone. It will also rely on a much newer technology for exoplanet hunting – the micro lens. The microlens itself has been around for a while and results in some absolutely spectacular astronomical images, such as the recently discovered “molten ring”. The technique uses a principle of relativity to take advantage of the fact that light can bend around massive objects like a star.
UT video about finding exoplanets.
If Roman finds a pair of stars that create a lens flare, he can see subtle changes in both stars in the system, allowing him to see transits in stars that are much further away than would otherwise be possible. In addition, lensing would add the unique ability to potentially detect planets that are on the opposite side of a star that is lensing. Any planets found using this technique would dim the light from the star that becomes microlensed, but only because it blocks that light before it reaches the gravitational pull of the star that is closer to Earth and orbits the planet.
This microlens technique could also be useful for finding another type of exoplanet. Known as “rogue planets”, these are not gravitationally tied to a star. Scientists have seen them in the past, but usually only when they are newly formed and emit infrared radiation. Roman has the potential to see hundreds more of these hikers, which helps to flesh out their creation process and evolution.
Graphic showing the searchable areas for each of the three major exoplanet hunting space telescopes. Roman will go much further than ever before.
Photo credit: NASA’s Goddard Space Flight Center
Rogue planets are likely to make up only a small percentage of the total number of planets discovered. An article was published a few years ago that discussed the two techniques and their uses. This article points out how Roman (then called WFIRST) in combination with the (hopefully) soon to be launched James Webb Space Telescope will bring all new observation possibilities online and really speed up the search for extrasolar planets. With luck, the planetary scientific community will have a cornucopia of new potential candidates to investigate over the next decade.
Learn more:
NASA – NASA’s Roman mission is set to find 100,000 planets in transit
The Cosmic Companion – Could the Nancy Grace Roman Telescope Find 100,000 Planets?
Digital trends – The upcoming Roman space telescope could discover 100,000 new exoplanets
UT – The Roman Space Telescope Nancy Grace could get its own star shadow
UT – There could be more rogue planets than stars in the Milky Way galaxy. This is how Nancy Grace will find her
Mission statement:
Artistic conception of a planetary transit.
Photo credit: JPL
Like this:
Loading…
Comments are closed.