What’s Up in the Sky – March, 2017
Planets have been in the news a lot lately. After an historic flyby of Pluto in 2015, the New Horizons spacecraft continues toward its next target, Kuiper Belt object MU69, a small (estimated diameter of 30 miles, maximum), icy world orbiting the Sun beyond the planet Neptune. New Horizons is due to arrive at MU69 on January 1, 2019.
Earlier this month the Juno spacecraft made its fourth close flyby of Jupiter, passing 2700 miles above the planet’s clouds. During the flyby instruments on the spacecraft probed beneath the cloud layers to gather information about the planet’s composition and structure. And there is still action at Saturn where the Cassini spacecraft, launched in 1997 and nearing the end of its mission, continues to make important discoveries as it passes through the gap between the planet and its rings.
These missions help us understand the newly discovered planets orbiting other stars which have been in the news most recently. Last Wednesday, scientists using NASA’s Spitzer Space Telescope announced the discovery of seven Earth-sized planets orbiting around a single star, the first such system to be detected. Three of the planets are located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water. All seven could have water, depending on their atmospheric conditions, but the chances are greatest for the three in the habitable zone. Named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile which discovered the first three last May, this exoplanet system is called TRAPPIST-1. Associate Administrator of the Science Mission Directorate at NASA, Thomas Zurbuchen said, “this discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life.” He went on to echo the sentiments of many astrophysicists by saying, “answering the question ‘are we alone’ is a top science priority”. The Trappist-1 discovery will greatly help scientists in their work to answer that question.
Closer to home, you have undoubtedly noticed bright Venus shining like a beacon with fainter Mars nearby (up and to the left) in the western sky after sunset. Early risers probably have noticed Jupiter gleaming in the southeast before dawn. If you are intrigued by these sights and would like more information regarding our solar system neighbors, check out the Planetary Society at www.planetary.org.
Founded in 1980 by Carl Sagan, Louis Friedman, and Bruce Murray, its mission is to “empower the world’s citizens to advance space science and exploration.” Now headed by Bill Nye (the “Science Guy”), the Planetary Society offers a treasure trove of information and resources for the general public. On its web site you can find articles on everything from current missions to the planets to protecting Earth from asteroid collisions. The Society is also the leading advocate for space science in Washington D.C. Check it out if you are looking for great source of information on what’s up in the sky.