Derrick Pitts, Chief Astronomer, The Franklin Institute
Take a look back on 2017 in space with this list of the top events and discoveries of the year relating to the cosmos from The Franklin Institute's chief astronomer, Derrick Pitts.
Astronomers were elated this year when the three operational gravitational wave observatories around the world all reported detecting gravitational waves from the collision of neutron stars and interactions between super-lightweight black holes in the outer reaches of the universe. Events like these that give insight into the early workings of the universe are so old and so distant that astronomers are unable to record their occurrence using conventional observing tools. Without LIGO, these event would be unknown. Now astronomers can use LIGO to detect and record similar events to add yet another layer to our understanding of how the universe was created and has evolved.
From the immense amount of data collected by the Kepler space probe, researchers have discovered the first distant solar system with the same number of planets as ours – eight. Although the system has no other similarities to ours (all eight planets are as close to their star as our Earth is to our Sun!), this discovery shows there’s a good possibility there could be many other systems with as many planets as our solar system. This discovery brings the total of confirmed exoplanets found by Kepler to 3,499!
This year, the continental United States experienced its first trans-continental total eclipse in nearly 100 years. It was intentionally observed by more people than any other science event in history. Space.com believes about 215 million people- 88 percent of the American population - saw the event in some way. The next total solar eclipse visible in the US will occur on April 8, 2024. It’s expected that even more people will try to see that solar eclipse.
Returning to Earth in early September after completing her most recent mission aboard ISS, Whitson became the most space-experienced astronaut ever. In total she’s spent 665 days in space. During those various missions to ISS she’s become the first woman mission commander twice, performed 10 space walks (the most ever for a female astronaut) and at the age of 57, the oldest woman astronaut ever!
After 20 years in space, and 13 years observing Saturn and its moons, the Cassini space probe ended its mission of discovery by making a steep dive into the atmosphere. This guaranteed complete incineration of the spacecraft and any potentially contaminating microbes that may have piggy-backed onboard from Earth. Cassini was one of the most successful spacecraft NASA sent out to collect data about the big and distant members of our solar system. Although the studies of Saturn itself gave us amazing information, the most exciting data collected by Cassini revealed a liquid water ocean beneath the icy crust of Saturn’s moon, Enceladus. Some scientists think the Enceladus ocean could be an environment conducive to the development of extraterrestrial life!
While NASA continues pulling together its plans for further human exploration of the solar system, both Elon Musk’s SpaceX and Jeff Bezos’ BlueOrigin have leapfrogged into leadership in the class of reuseable and reliable launch vehicles. SpaceX has now completed 18 controlled vertical landings and Blue Origin has upped their vertical landing game by performing the softest surface landings of any spacecraft ever – as little as 1 mile per hour! While neither has yet to do more that deliver cargo to ISS, both have very ambitious plans to completely rewrite the guidebook on sending people to the moon and to Mars safely and quickly – and probably before NASA does!
This fall, our solar system was visited by an interstellar traveler, a solar system-hopping asteroid. For perhaps the first time ever, astronomers sighted what’s now described as an interstellar asteroid – one that has unintentionally encountered several solar systems as its motion carries it through the galaxy. Although the cylindrical shape is unusual for an asteroid, that doesn’t call for its identification as an artificially created object either. Such speculation that the object could be an alien spacecraft is most likely driven by Arthur C. Clarke’s 1973 sci-fi novel “Rendezvous with Rama”, where a cigar-shaped alien spacecraft comes to visit our solar system. Radio telescope studies to determine its composition have not detected any radio emissions coming from the asteroid. Having already passed our sun, the asteroid named ‘Oumuamua’, is already on its way towards the outer solar system, expected to pass Jupiter about a year from now.
The $100 million ‘Breakthrough Starshot’ initiative intends to develop, within a generation, the capability to launch tiny laser-propelled space probe chips to the nearest star. The 1-gram, postage stamp-sized chips would have all the electronics necessary to collect data and transmit information back to us from the nearest star system. Driven by 100-gigawatt lasers, the chips would accelerate up to 20% of the speed of light in two minutes arriving at the 4-light year distant star Alpha Centauri in 20 years. The project is funded by Russian billionaire Yuri Milner and is supported by Stephen Hawking and Mark Zuckerberg. The proposed project could cut 29,980 years off a conventionally propelled space probe sent out to Alpha Centauri. Milner has also promised $100 million for ‘Breakthrough Listen’, a project surveying 1 million of the closest stars in the Milky Way, and $1 million for ‘Breakthrough Message’ for the best message to send to any listening intelligent life.
In early December President Trump signed a space policy directive formally directing NASA to immediately undertake efforts return humans to the moon as the first step towards building American capability to send people to Mars. The directive also provides focus for NASA’s work towards deep solar system exploration leaning on a ‘stepping stone’ approach that starts with developing the moon as a way-station for human exploration.
For the first time ever, exoplanet researchers have identified a planetary system 39 light years away where all seven planets are earth-sized and three of those are in the star’s habitable zone. A ‘habitable zone’ is the region around a star where the temperature is just right for liquid water on a planet’s surface. For this system’s ultracool dwarf star, the habitable zone is very close to the star. The three habitable zone planets have orbits of 6, 9, and 12 days, just a minute fraction of orbital speeds of planets in our solar system. Discovered using the relatively small TRAPPIST-1 telescope mounted under the very dark skies in Chile, the star is just a bit bigger than our planet Jupiter. While the discovery of so many earth-sized and habitable zone planets is ground-breaking, so too is the fact that the star is an ultracool dwarf, the most numerous type of stars found in galaxies.
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