Space discoveries in 2019

This 17 June 2019 video says about itself:

Space is amazing. Over the years, NASA’s revealed some unusual mysteries about it. Lets find out amazing the most amazing recent discoveries made in space!

By Maria Temming, December 23, 2019 at 7:00 am:

How 2019’s space missions explored distant worlds

Planets, asteroids and Arrokoth were the focus of new discoveries

From asteroids to exoplanets, spacecraft are leaving no space rock unturned. While agencies in China, India and Israel made headlines with missions to the moon, here are some other places that space probes scouted in 2019.

Zoom and enhance

Touring Pluto in 2015 may have been New Horizons’ main event (SN: 12/26/15, p. 16), but flying by what used to be called Ultima Thule was an awesome encore. The space probe zipped by this Kuiper Belt object, now called Arrokoth, on New Year’s Day (SN Online: 12/30/18). Scientists were on the edge of their seats as the probe snapped pictures and sent higher- and higher-resolution images over several weeks, revealing the visage of Arrokoth to look like an elongated blob, then a snowman and finally a pair of lumpy pancakes (SN: 3/16/19, p. 15). Uncovering the origins of Arrokoth’s awkward shape may lend insight into the early stages of planet formation (SN: 4/13/19, p. 11).

I spy exoplanets

NASA’s Transiting Exoplanet Survey Satellite, or TESS, racked up eight exoplanet finds in its first few months of observation (SN: 2/2/19, p. 12). That initial cache included some weirdos, such as a planet that is about as dense as pure water and a “lava world” known as LHS 3844b that sizzles at about 540° Celsius. TESS has since discovered a new type of exoplanet called an ultrahot Neptune, which appears to be a fluffy gas giant in the process of stripping down to its rocky core (SN: 8/31/19, p. 11).

Asteroids to go

The Japan Aerospace Exploration Agency’s Hayabusa2 is expected to become the second spacecraft ever to bring a bit of asteroid back to Earth, after the original Hayabusa probe returned with a souvenir from the asteroid Itokawa in 2010. Hayabusa2 touched down on the asteroid Ryugu in February to fetch a sample from the asteroid’s surface (SN Online: 2/22/19). Then, to get a deeper sample, Hayabusa2 fired a copper projectile at Ryugu to punch a crater into the asteroid (SN Online: 4/5/19). The probe then ducked down to snag some rubble excavated from the interior (SN: 8/17/19, p. 14). Scientists won’t know exactly how much of Ryugu was collected until Hayabusa2, which started its journey home on November 13, arrives at Earth in late 2020.

Another sample-return mission, NASA’s OSIRIS-REx, is still orbiting its asteroid. When the spacecraft first arrived at Bennu in December 2018, observations unveiled a rugged surface littered with boulders — bad news for a probe designed to navigate more beachlike terrain (SN: 4/13/19, p. 10). Using OSIRIS-REx’s detailed mapping of Bennu from orbit, NASA selected a site for sample collection in the asteroid’s northern hemisphere (SN Online: 12/12/19). Bits of Bennu, to be returned in 2023, may reveal whether a similar asteroid could have delivered to early Earth a molecular starter pack for life (SN: 1/19/19, p. 20).

Meanwhile, on Mars

InSight arrived on the Red Planet in November 2018, and the rookie lander may have already captured the first recording of a Marsquake (SN Online: 4/23/19). Unlike tremors on Earth, underground rumblings on Mars are thought to result from the planet contracting as it cools. Studying such seismic signals could help scientists better understand the structure of Mars’ deep interior.

While InSight had its ear to the ground, the veteran Curiosity rover was measuring the consistency of a Martian mountain (SN Online: 1/31/19). As Curiosity scaled Mount Sharp, accelerometer readings indicated surprisingly loose rock beneath the rover’s wheels — suggesting that winds formed the mountain by sweeping sediment into a giant pile.

Ultimate Thule minor planet renamed Arrokoth

Arrokoth appears as a ruddy deformed snowman in this composite image acquired by NASA’s New Horizons spacecraft as it sped past on January 1, 2019. NASA, Johns Hopkins University Applied Physics Laboratory, Southwest Research

By Christopher Crockett, 13 November 2019:

NASA gave Ultima Thule a new official name

The far-flung solar system body is now Arrokoth, the Powhatan word for ‘sky’

Ultima Thule is no more. The remote solar system body visited in January by NASA’s New Horizons spacecraft now has a proper name: Arrokoth.

The word means “sky” in the language of the Powhatan people, a Native American tribe indigenous to Maryland. The state is home to New Horizons mission control at the Johns Hopkins University Applied Physics Laboratory in Laurel.

“We wanted to honor Maryland as our mission epicenter, and the idea of using a Native American language from there just bubbled up,” says Alan Stern, head of the New Horizons mission and a planetary scientist at the Southwest Research Institute in Boulder, Colo. “Tying it to our mission by using the word ‘sky’ completed the trifecta.”

NASA announced the name change on November 12, with the consent of Powhatan tribal elders and the International Astronomical Union, the organization of astronomers who, in part, oversee celestial naming conventions.

Arrokoth (pronounced AR-uh-koth), a flattened two-lobed body in the Kuiper Belt of icy worlds beyond Neptune, has been through a couple of names already. Up until now, its official designation had been 2014 MU69. In March 2018, the team landed on the nickname Ultima Thule, a Latin phrase that signifies a place beyond the known world.

“[Ultima Thule] was, as we said, always a placeholder we would discard once we did the flyby,” Stern says. That moniker came under almost immediate criticism after Newsweek noted that the phrase had also been appropriated by the Nazis as the mythical homeland of the Aryan race.

The New Horizons spacecraft — originally sent to check out Pluto and its retinue of moons (SN: 7/26/15) — is still transmitting data from its January 1 flyby of Arrokoth (SN: 1/2/19) and will continue to do so for at least another year, Stern says. By then, the team will have begun hunting for a possible third target, a search they can’t start until Earth gets to the other side of the sun next summer and New Horizons once again becomes visible at night to telescopes.

Hubble telescope’s water discovery on exoplanet

This 11 September 2019 video from NASA in the USA says about itself:

With data from the Hubble Space Telescope, water vapor has been detected in the atmosphere of an exoplanet within the habitable zone of its host star.

K2-18b, which is eight times the mass of Earth, is the only planet orbiting a star outside the solar system (or “exoplanet”) within the habitable zone.

This may be the first known exoplanet with rain and clouds of water droplets. Two teams have detected signs that K2 18b has a damp atmosphere: here.

See also here.

Researchers have described a new, lower size limit for planets to maintain surface liquid water for long periods of time, extending the so-called Habitable or ‘Goldilocks’ Zone for small, low-gravity planets. This research expands the search area for life in the universe and sheds light on the important process of atmospheric evolution on small planets: here.

Why just being in the habitable zone doesn’t make exoplanets livable. Debate over what makes a planet habitable highlights the trickiness in searching for alien life: here.

Sunset timelapse video from space

This 3 June 2019 NASA video says about itself:

Sunset Timelapse from the International Space Station

Enjoy this sped-up Earth view, captured by the Expedition 59 astronauts currently onboard the International Space Station. The station orbits the Earth every 90 minutes — meaning this sunset you see is actually one of 16 the station residents see each day!

Astronomical and spaceflight update

This video says about itself:

JAXA’s Asteroid Explorer “Hayabusa2” collected a sample from asteroid Ryugu on 22 February 2019. The touchdown was captured using the onboard small monitor camera (CAM-H). The image of the site immediately after touchdown was taken with the Optical Navigation Camera – Wide angle (ONC-W1) on 22 February 2019.

Ryugu is probably a chip off one of these two other asteroids. Japan’s Hayabusa2 team has narrowed down the asteroid’s origins based on its color. By Lisa Grossman, 3:20pm, March 20, 2019.

This video says about itself:

NASA’s OSIRIS-REx mission returned the first scientific observations, revealing that asteroid Bennu is an active asteroid. OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) is the first U.S. mission to sample an asteroid (near-Earth asteroid Bennu), retrieve surface material and return it to Earth for study in September 2023. Dante Lauretta, OSIRIS-REx principal investigator, explained the findings in a media teleconference.

Surprising astronomers, Bennu spits plumes of dust into space. It’s the first time astronomers have seen such activity on an asteroid. By Lisa Grossman, 2:55pm, March 19, 2019.

X-ray ‘chimneys’ connect the Milky Way to mysterious gamma-ray bubbles. Two glowing columns hundreds of light-years long extend from the center of the galaxy. By Emily Conover, 2:00pm, March 20, 2019.

Dwarf planet Ultima Thule flatter than thought

This 8 February 2019 video says about itself:

Ultima Thule is Flatter Than Previously Thought

NASA New Horizons‘ imagery of the Kuiper Belt Object has revealed its true shape.

Ultima Thule is shaped like two lumpy pancakes. New images reveal the skinny side of the Kuiper Belt object. By Emily Conover, 6:00pm, February 8, 2019.

Ultima Thule may be a frankenworld, Astronomers are closer to uncovering the distant space rock’s origin story. By Lisa Grossman, 5:35pm, March 18, 2019.