Dwarf planet Haumea has ring


This video says about itself:

The Weirdest Planet Got Weirder – Haumea Has Rings

12 October 2017

Back in January the planet Haumea passed in front of a star, and a Spanish team were observing, using the occultation timings to measure the size and shape of this distant body. And in the process discovered a ring system around this already strange and mysterious body.

By Lisa Grossman, 1:00pm, October 11, 2017:

Oddball dwarf planet Haumea has a ring

It’s the first object past Neptune in the solar system known to have debris circling it

Haumea can do the hula-hoop. The egg-shaped dwarf planet is the first object beyond Neptune to be spotted sporting a ring of particles.

“It now appears that rings can be common in the outer solar system,” says Jose-Luis Ortiz of the Institute of Astrophysics of Andalusia in Granada, Spain.

On January 21, Ortiz and colleagues used 12 telescopes at 10 observatories to peer into the Kuiper Belt, a region of icy objects beyond the orbit of Neptune, and watch Haumea block the light of a distant star. That tiny eclipse let the team measure the dwarf planet’s size, shape and surrounding environment more accurately than ever before.

Haumea turned out to be larger — its long axis stretches at least 2,322 kilometers, a bit more than half the width of the contiguous United States — and less dense than previously thought, the team reports October 11 in Nature. To their surprise, the researchers also saw the background star flicker before and after its light was blocked by Haumea itself. That flicker is consistent with a 70-kilometer-wide ring about 1,000 kilometers above the dwarf planet’s surface.

The ring is probably made of rock and ice, Ortiz says, but more observations are needed to know for sure. It could be debris kicked up by impacts from small stray space rocks — or even just from the dwarf planet’s spinning. Haumea twirls unusually fast, completing a rotation once every 3.9 hours, which could help fling particles into orbit.

Until recently, the four giant planets — Jupiter, Saturn, Uranus and Neptune — were the only solar system bodies known to have rings. Then in 2014 and 2015, astronomers spotted rings around the tiny planetoids 10199 Chariklo (SN: 5/3/14, p. 10) and 2060 Chiron, suggesting that small bodies could hold on to rings, too.

Both of those small worlds are known as centaurs, objects whose orbits take them between Jupiter and Neptune, although they may be interlopers from the more distant Kuiper Belt. Since recent searches for rings around Pluto came up empty (SN Online: 10/4/17), no object farther away than Neptune seemed to have rings. Some astronomers speculated that something about the Kuiper Belt disrupted rings around small worlds there, or that the centaurs got their rings as part of the process that kicked them into their current orbits. Haumea’s ring suggests that such structures can form and survive at the solar system’s fringes after all.

“This discovery does disrupt that tidy narrative,” says Matthew Tiscareno of the SETI Institute in Mountain View, Calif., who studies Saturn’s rings but was not involved in the new study “Reality is more complicated — that is, interesting.”

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Voyager 1,2 spacecraft news


This video says about itself:

See Two Spacecraft Journey to Outer Reaches of Solar System | National Geographic

16 September 2017

After 40 years of service, the two Voyager spacecraft are heading deeper into the cosmos, with Voyager 1 holding the record as the farthest human-made object.

Birds, hurricanes and solar eclipses


This video from Texas in the USA says about itself:

26 August 2017

A Houston taxi driver made an unusual friend during Hurricane Harvey. William Bruso returned to his taxi after getting food to find a hawk sitting on the passenger seat. Dubbed Harvey, the Cooper’s hawk refused to leave his shelter. Bruso made sure the bird wasn’t injured and tried to release him but Harvey seemed unwilling to brave the storm on his own. Eventually, Bruso agreed to let the hawk stay until the hurricane has passed.

The hawk was later set free.

From the Cornell Lab of Ornithology in the USA:

What Happens to Birds In Hurricanes?

Our hearts go out to all whose lives have been affected by Hurricanes Harvey and Irma. We have also received questions about how hurricanes affect birds. See our article on hurricanes and migration or check the special reports from our BirdCast team summarizing observations from eBirders who are documenting birds in the wakes of Hurricanes Irma and Harvey.

Little is known about longer-term effects of hurricanes on birds. Contribute your observations at eBird.org.

BirdCast Also Reported on Birds and the Eclipse: More than 1,200 eBirders submitted checklists on August 21 during the maximum eclipse in their area. Nighthawks suddenly emerged, magpies flocked to roost, and warblers looked like they were getting ready for a night of migration. Read more from BirdCast.

Cassini spacecraft’s suicide on Saturn


This video says about itself:

Cassini‘s Fatal Crash | Mission Saturn

13 September 2017

A three billion dollar spacecraft is hurtling towards destruction– but it’s no accident.

NASA’s biggest spacecraft plunges into Saturn in the final act of a 20-year mission showcasing the planet like never before.

IT’S BEEN A GOOD RUN “NASA’s Cassini spacecraft will end its groundbreaking 13-year mission to Saturn on Friday with a meteor-like plunge into the ringed planet’s atmosphere, transmitting data until the final fiery moment.” [Reuters]

These are Cassini’s parting shots of the Saturn system: here.

R.I.P. Cassini. After 20 years, nearly 300 orbits and pioneering discoveries, the spacecraft plunges to its death in Saturn’s atmosphere. By Lisa Grossman, 9:08am, September 15, 2017.

Saturn’s moons research


This video says about itself:

Exploring Saturn’s Moons | Mission Saturn

13 September 2017

On a flyby of Saturn‘s moon Enceladus, the Cassini spacecraft makes an unprecedented discovery that will push the mission to fly closer.

About Mission Saturn: NASA’s biggest spacecraft plunges into Saturn in the final act of a 20-year mission showcasing the planet like never before.

Final flyby puts Cassini on a collision course with Saturn, by Lisa Grossman. 4:00pm, September 11, 2017.

So long, Titan. Cassini snaps parting pics of Saturn’s largest moon, by Lisa Grossman, 4:05pm, September 13, 2017.

Dwarf planet Pluto features get official names


Pluto features named

From the International Astronomical Union:

7 September 2017

Pluto Features Given First Official Names

The Working Group for Planetary System Nomenclature (WGPSN) of the International Astronomical Union (IAU) has officially approved the naming of fourteen features on the surface of Pluto. These are the first geological features on the dwarf planet to be named following the close flyby by the New Horizons spacecraft in July 2015.

The IAU has assigned names to fourteen geological features on the surface of Pluto. The names pay homage to the underworld mythology, pioneering space missions, historic pioneers who crossed new horizons in exploration, and scientists and engineers associated with Pluto and the Kuiper Belt. This is the first set of official names of surface features on Pluto to be approved by the IAU, the internationally recognised authority for naming celestial bodies and their surface features.

NASA’s New Horizons team proposed the names to the IAU following the first reconnaissance of Pluto and its moons by the New Horizons spacecraft. Some of the names were suggested by members of the public during the Our Pluto campaign, which was launched as a partnership between the IAU, the New Horizons project and the SETI Institute. Other names had been used informally by the New Horizons science team to describe the many regions, mountain ranges, plains, valleys and craters discovered during the first close-up look at the surfaces of Pluto and its largest moon, Charon.

“We’re very excited to approve names recognising people of significance to Pluto and the pursuit of exploration as well as the mythology of the underworld. These names highlight the importance of pushing to the frontiers of discovery,” said Rita Schulz, chair of the IAU Working Group for Planetary System Nomenclature. “We appreciate the contribution of the general public in the form of their naming suggestions and the New Horizons team for proposing these names to us.”

More names are expected to be proposed to the IAU, both for Pluto and for its moons. “The approved designations honour many people and space missions who paved the way for the historic exploration of Pluto and the Kuiper Belt, the most distant worlds ever explored,” said Alan Stern, New Horizons Principal Investigator from the Southwest Research Institute (SwRI) in Boulder, Colorado.

The approved Pluto surface feature names are listed below.

Tombaugh Regio honours Clyde Tombaugh (1906–1997), the U.S. astronomer who discovered Pluto in 1930 from Lowell Observatory in Arizona.

Burney crater honors Venetia Burney (1918–2009), who as an 11-year-old schoolgirl suggested the name “Pluto” for Clyde Tombaugh’s newly discovered planet. Later in life she taught mathematics and economics.

Sputnik Planitia is a large plain named after Sputnik 1, the first space satellite, launched by the Soviet Union in 1957.

Tenzing Montes and Hillary Montes are mountain ranges honouring Tenzing Norgay (1914–1986) and Sir Edmund Hillary (1919–2008), the Indian/Nepali Sherpa and New Zealand mountaineer who were the first to reach the summit of Mount Everest and return safely.

Al-Idrisi Montes honours Ash-Sharif al-Idrisi (1100–1165/66), a noted Arab mapmaker and geographer whose landmark work of medieval geography is sometimes translated as “The Pleasure of Him Who Longs to Cross the Horizons.”

Djanggawul Fossae defines a network of long, narrow depressions named for the Djanggawuls, three ancestral beings in indigenous Australian mythology who travelled between the island of the dead and Australia, creating the landscape and filling it with vegetation.

Sleipnir Fossa is named for the powerful, eight-legged horse of Norse mythology that carried the god Odin into the underworld.

Virgil Fossae honors Virgil, one of the greatest Roman poets and Dante’s fictional guide through hell and purgatory in the Divine Comedy.

Adlivun Cavus is a deep depression named for Adlivun, the underworld in Inuit mythology.

Hayabusa Terra is a large land mass saluting the Japanese spacecraft and mission (2003–2010) that returned the first asteroid sample.

Voyager Terra honours the pair of NASA spacecraft, launched in 1977, that performed the first “grand tour” of all four giant planets. The Voyager spacecraft are now probing the boundary between the Sun and interstellar space.

Tartarus Dorsa is a ridge named for Tartarus, the deepest, darkest pit of the underworld in Greek mythology.

Elliot crater recognises James Elliot (1943–2011), an MIT researcher who pioneered the use of stellar occultations to study the Solar System — leading to discoveries such as the rings of Uranus and the first detection of Pluto’s thin atmosphere.

American animals react to solar eclipse


This video from the USA says about itself:

21 August 2017

Wild animals react to the 2017 Total Eclipsered squirrels barking, tree frogs croaking and crickets and other night insects chirping! Total eclipse of the sun over the Great Smoky Mountains – with night-time cricket, frogs and other critter noises coming from the deep forest after the darkness of totality starting about 1:30 into the video and then back to normal. We fought off clouds and just managed to get a window at max eclipse time. This was filmed with no filters at all with a Tamron 150-600 mm Canon zoom.

This video from the USA says about itself:

21 August 2017

Forest animals react to the total darkness of the 2017 eclipse. I put a camera back in the forest just to record the sounds as day turned to night. Listen for the barking and alarm call of Red Squirrels, Eastern Towhees, chickadees and some doves crashing into tree branches as they freak out in the dark. Also interesting is a distant human screaming as the eclipse reaches totality. Sound really travels in the mountain forest. Filmed in the Great Smoky Mountains. If you want to skip right to the dark part it starts at 3:00.

What Do Birds Do During a Total Eclipse? Observations from eBird and Radar on August 21, 2017: here.