This year brought many strangely divergent events in space exploration and astronomy. Robotic spacecraft explored new worlds in our own solar system, while researchers discovered dozens of new exoplanets many light years away. Closer to home, NASA continued to research exotic new technologies needed for deep-space exploration, while at the same time seemingly routine supply missions to the International Space Station failed in spectacular fashion. Here are 10 space stories that made headlines in 2015, several of which are still evoking wonder and debate in the scientific community.
10. NASA Tests ‘Flying Saucer’
Mention the phrase “NASA to test flying saucer,” and you will create a social media buzz of epic proportions. Known as the LDSD or Low-Density Supersonic Decelerator, the bizarre-looking, doughnut-shaped vehicle is designed to test a reentry system needed to land large loads on Mars. This capability is crucial for any potential crewed missions to the Red Planet. NASA conducted a test of this “flying saucer” June 8 at the Pacific Missile Range Facility in Hawaii. While the Supersonic Inflatable Aerodynamic Decelerator (SIAD) deployed successfully, the parachute suffered damage during the test. Expect further tests in 2016.
9. Is Strange Discovery an Alien Megastructure?
Astronomers continue to debate the cause of strange flickers spotted around a distant star, known as KIC-8462852. Volunteers at the Planet Hunters Project noticed an erratic pattern in the usual characteristic dip in light seen when a planet passes in front of its host star. Although the main explanation put forth by astronomers is a swarm of comets, a more exotic explanation captured popular imagination: could it be an enormous alien structure? Although controversial, researchers considered the idea seriously enough that SETI scanned the system for radio signals; thus far, nothing has turned up in the system 1,480 light years distant.
The concept of an alien civilization theoretically building a massive array of solar panels to encircle its home star has been around for decades, but chances are, there is a much more plausible explanation for KIC-8462852. As Universe Today noted, “In the end, it’s probably not an alien megastructure, just like the first pulsar signals weren’t sent by … Little Green Men.”
8. Dawn Reaches Dwarf Planet Ceres
NASA’s Dawn spacecraft reached Ceres earlier this year, giving us our first close-up views of the only dwarf planet in the asteroid belt. Dawn fired its ion engines and entered orbit around Ceres on March 6 and commenced science and mapping operations. The first surprise: the spacecraft found more than 130 “bright areas” all over Ceres. The brightest and most notable is the giant Occator crater. Scientists are still not sure what created the bright spots, but one theory suggests they are a type of salt, raising questions about the dwarf planet’s composition. By the way, the Dawn spacecraft became the first mission to orbit two separate destinations beyond the Earth; in 2011, the craft visited Vesta, a giant protoplanet. Dawn will remain permanently in orbit around Ceres, and will approach in ever-closer mapping orbits.
7. Several Spacecraft Lost After Launch
2015 proved to be a very bad year for cargo spacecraft headed to the ISS. The problems actually started in October 2014, when an Orbital Sciences Antares rocket exploded shortly after takeoff from Wallops Island, Virginia. In April, a routine Russian Progress supply vehicle began spinning wildly in orbit, and was lost when it reentered a few days later. Then, on June 28, a SpaceX Dragon capsule also headed for the ISS exploded 139 seconds after liftoff from Cape Canaveral. Although the astronauts aboard the station were never in any danger — they are well stocked, and can go up to six months without resupply, plus other missions made it through — the losses highlight lingering issues surrounding the privatization of space and reliance on international cooperation.
6. Blue Origin’s Spacecraft Takes Flight
Jeff Bezos surprised everyone last month with a sub-orbital test of his new spacecraft. The Amazon CEO turned-spaceflight entrepreneur announced that his company carried out a successful test of its New Shepard rocket and capsule on Nov. 23. Launched from a remote west Texas launch site, the rocket reached an altitude of around 62 miles, just above the Karman line demarcating the beginning of space, before returning to Earth for a dramatic Buck Rogers-style “fins-first” landing. Blue Origin hopes to ultimately take space tourists on short sub-orbital hops in the near future.
5. Astronauts Embark on One-Year Space Mission
Astronauts started long-duration space missions aboard the International Space Station this year. The goal: to find out how astronauts would fare physiologically on a manned mission to Mars and possibly beyond. Astronaut Scott Kelly and cosmonaut Mikhail Korniyenko blasted off from the Baikonur Cosmodrome in Kazakhstan on March 27 to begin a 342-day mission. Kelly has already broken a U.S. spaceflight record for the longest cumulative time in space on Oct. 16 at 383 days; he’ll also set a NASA record for single-mission duration upon his return. This will, however, still fall far short of cosmonaut Valeri Polyakov’s 437-day stay aboard Mir. Kelly was selected for another reason: he’s the twin of astronaut Mark Kelly, making the pair an ideal study on the physiological effects of long-term space travel.
4. Astronomers Spot Most Distant Object in Solar System
In early November, astronomers announced the discovery of the most distant object yet observed in the solar system. Dubbed V774104, the Trans-Neptunian Object is currently 103 times farther from the Sun than the Earth, or almost three times farther from the Sun than Pluto. It’s perhaps 500 to 1,000 kilometers in size. Further observations will be needed to pin down V774104’s orbit. The discovery was made using the Subaru telescope atop Mauna Kea.
3. Exoplanet Count Grows With Exciting Discoveries
It’s hard to believe, but about two decades ago, no planets beyond our solar system were known; now, the current number of confirmed exoplanets sits at 2,026 and counting. Highlights from 2015 discoveries include Kepler 452b, a “super-Earth” discovery 60% more massive than our planet in a 385-day orbit around a Sun-like star; and GJ 1132b, a rocky Earth-sized world a relatively close 39 light years distant. The next step will be to target these and other recently discovered worlds for direct imaging and spectroscopic analysis, and it’s not out of the realm of possibility that we may soon know if anything chemically interesting is happening on these worlds.
2. Cassini Has Close Encounter With Enceladus
Could Saturn’s moon harbor a subsurface ocean? NASA’s Cassini spacecraft has been wrapping up operations around Saturn in 2015, giving us amazing views of its moons. On Oct. 28, Cassini flew past the southern pole of Saturn’s icy moon Enceladus, sampling the spray of some of its ice plumes jetting into space. Cassini has revealed the moon to be active, similar to Jupiter’s moon Europa; like Europa, it may have an extensive ocean complete with geothermal heating under its icy exterior. It’s no wonder that, like Europa, Enceladus is on NASA’s short list for worlds that may harbor life in the solar system. It may be worthy of a targeted mission one day.
1. New Horizons Reaches Pluto
Easily the biggest space news story of 2015, NASA’s New Horizons spacecraft reached Pluto this year on July 14, flying just 7,800 miles above the surface of the distant world. Launched in January 2006, it took New Horizons more than nine years to reach its intended target. New Horizons revealed Pluto, its giant moon Charon, and tinier moons in amazing detail, showing active worlds in stark contrast with a varying terrain that still confounds scientists. New Horizons also looked back at Pluto after the flyby, showing its atmosphere back-lit by the distant Sun. The data retrieval rate is so slow over such a great distance that we’re still getting new images from New Horizons. The next port of call for the spacecraft is the tiny Kuiper Belt Object 2014 MU69 on New Year’s Day 2019.