By Dr. Ed Albin
Program Director, Space Studies
Since the discovery of the first exoplanet in 1995, astronomers have found thousands of predominantly large planets orbiting other stars. Most recently, the discovery of a solar system with seven smaller Earth-like planets generated much excitement among astronomers and laymen alike.
Scientists are excited about the potential for life on these planets, because these new worlds are similar in size to the Earth. Their proximity to their sun might mean that some of them could hold the water necessary to sustain life.
These exoplanets are about 40 light years away, orbiting a relatively “nearby” star called Trappist-1. This star is what astronomers call a “red dwarf,” because it is considerably smaller than our sun.
Environmental Conditions on New Planets Appear Favorable to Life
Trappist-1 radiates enough heat to warm its nearby planets. Several of them are within the star’s habitable zone — a place where liquid water can exist. These planets are neither too close to the star, which could cause water to boil away; nor too far from the star, which would freeze any water on each planet.
A group of astronomers led by the University of Liege in Belgium discovered these new exoplanets. After weeks of observation using NASA’s Spitzer Space Telescope, the team confirmed that there were seven planets orbiting the little star.
These planets have between 40 percent and 140 percent of Earth’s mass and orbit their host star at a distance closer than Mercury is to the sun. The Hubble Space Telescope is now searching for evidence of atmospheres associated with the planets.
Astronomers Will Use the James Webb Space Telescope to Look for Oxygen or Methane Gases
Astronomers hope the James Webb Space Telescope, due to be launched soon, might be able to decipher the chemistry of any atmospheres that are found on these new planets. The presence of oxygen and/or methane could be the “fingerprint” of life.
Because the Trappist-1 planetary system is tightly bunched around the star, asteroid strikes might have scattered life across these worlds. Such planets are perfect candidates for SETI (Search for Extraterrestrial Intelligence) programs, like the one at the SETI Institute in California. At SETI, an array of radio telescope dishes regularly sweeps the heavens in search of extraterrestrial signals sent by advanced civilizations out there among the stars.
Our Telescope Will Collect Photometric Data on Stars with Orbiting Exoplanets
The University’s Space Studies faculty and students are thrilled about the Trappist-1 system discovery. The recently commissioned APUS Observatory, in Charles Town, West Virginia, is capable of conducting follow-up observations of newly discovered exoplanets.
Our state-of-the-art, remote-controlled 24-inch telescope can collect photometric data in the form of light variations from stars with orbiting exoplanets. These variations appear as a slight dimming of the star when a planet moves across its stellar disk, causing a minuscule drop in brightness.
The sensitivity of the digital camera on our telescope is capable of detecting these subtle changes in brightness, providing additional details about distant alien worlds.
It is an exciting time for astronomy, making it even more thrilling as we launch our new astronomy concentration in Space Studies later this year.