Monthly Archives: December 2020

Japanese space capsule carrying pristine asteroid samples lands in Australia

For the second time ever, humanity has brought asteroid samples down to Earth. A small capsule bearing pristine pieces of the near-Earth asteroid Ryugu touched down early this afternoon (Dec. 5) within the remote and rugged Woomera Prohibited Area, about 310 miles (500 kilometers) northwest of the South Australian capital of Adelaide. The samples were snagged millions of miles from Earth by Japan’s Hayabusa2 mission, which studied the 3,000-foot-wide (900 meters) Ryugu up close from June 2018 to November 2019.

Hayabusa2’s predecessor was the first to haul space-rock samples home, delivering pieces of the stony asteroid Itokawa in 2010. But the original Hayabusa (Japanese for “peregrine falcon”) returned less than 1 milligram of material. Hayabusa2’s bounty is expected to exceed 100 mg (0.0035 ounces), and its samples come from a very different kind of asteroid — a primitive “C-type” space rock rich in water and carbon-containing organic compounds. “The materials that formed the Earth, its oceans and life were present in the primordial cloud from which our solar system formed. In the early solar system, these materials were in contact and able to chemically interact within the same parent objects,” Japan Aerospace Exploration Agency (JAXA) officials wrote in an overview of Hayabusa2. “These interactions are retained even today in primitive bodies (C-type asteroids), so returning samples from these bodies for analysis will elucidate the origins and evolution of the solar system and the building blocks of life,” they added.

On Mars, internal heat may have powered habitable hotspots long ago

If life emerged on ancient Mars, it may have had the planet’s internal heat to thank. The Martian underground may have been habitable billions of years ago even if the planet’s surface was a dry, frigid wasteland. Mars likely churned out enough geothermal heat in the ancient past to melt the bases of thick ice sheets, generating large amounts of potentially life-supporting groundwater, a new study suggests. The results could help scientists get a better handle on a decades-old mystery known as the faint young sun paradox. Four billion years ago, the sun was about 30% dimmer than it is today — too weak, seemingly, to support a continuously warm and wet Mars. Yet evidence of liquid water during that epoch abounds; NASA’s Mars rover Curiosity, for example, has spent the last eight years exploring an ancient lake-and-stream system. Hence the paradox.

“Even if greenhouse gases like carbon dioxide and water vapor are pumped into the early Martian atmosphere in computer simulations, climate models still struggle to support a long-term warm and wet Mars,” study lead author Lujendra Ojha, an assistant professor at Rutgers University-New Brunswick in New Jersey, said in a statement. “I and my co-authors propose that the faint young sun paradox may be reconciled, at least partly, if Mars had high geothermal heat in its past,” Ojha said. He and his colleagues investigated whether the required internal heat — generated by the radioactive decay of elements such as thorium, potassium and uranium — did indeed flow during Mars’ Noachian era, which lasted from about 4.1 billion to 3.7 billion years ago. The researchers focused their attention on the Martian southern highlands, a region that likely supported large ice sheets at the time.

Virgin Galactic prepares for low-key first spaceflight from New Mexico

When Virgin Galactic’s SpaceShipTwo takes to the skies above New Mexico later this month, it will do so without the crowds and publicity once expected for the historic flight. Virgin Galactic announced Dec. 1 that is had rescheduled a powered test flight of its SpaceShipTwo suborbital spaceplane for a window that opens Dec. 11 from Spaceport America in New Mexico. Pilots CJ Sturckow and David Mackay will fly the vehicle on trajectory that will go above the 80-kilometer altitude that the company defines as space, based on the altitude U.S. government agencies use for awarding astronaut wings. The vehicle will then glide to a landing at the spaceport.|

Virgin had scheduled the launch for last month, but postponed it Nov. 16 when the state imposed a new stay-at-home order to address a sharp increase in COVID-19 cases. That order closed nonessential businesses and placed restrictions on those allowed to remain open. That stay-at-home order has been replaced with a “Red to Green Framework” that sets restrictions on a county-by-county basis. Nearly every county in New Mexico, though, is in the highest, or “red,” category, including where Spaceport America is located. That category does allow nonessential businesses to open, but at significantly reduced capacity. Virgin Galactic said it would proceed with the test flight using only “essential personnel” at the spaceport. “Only essential staff will be on-site to support the pre-flight operations ahead of the flight and the day of flight,” the company said in a statement, adding that there will be no guests or media at the spaceport to witness the flight.