A Distant Planet May Lurk Far Beyond Neptune

If Planet X exists, it may be anywhere from 250 to 1,000 times as far from the sun as Earth

By Christopher Crockett

Out beyond Neptune, the solar system resembles the deep ocean: dark, remote and largely unexplored. To an Earth-bound observer, even the brightest objects, such as Pluto, are 4,000 times as faint as what the human eye can see.

An undiscovered planet could easily lurk out there unnoticed, a possible fossil from a time when the giant planets jockeyed for position 4 billion years ago, scattering planets and asteroids in their wake. But even the largest telescopes would struggle to find such a faint spot of light. Most likely, the clues would be entangled in the distorted orbits of faraway ice boulders tumbling around the sun.

Astronomers Chad Trujillo and Scott Sheppard provided a hint about how such a world might reveal itself last March when they announced the discovery of a 450-kilometer-wide dwarf planet just outside the Kuiper belt — the icy debris field past Neptune (SN: 5/3/14, p. 16). 

Their find, designated 2012 VP113, is on a course that loops around the sun in a vastly elongated orbit far from the known planets. It has thousands of neighbors but shares its odd trajectory only with Sedna, another dwarf planet, discovered in 2003…

(read more: Science News)

images: E. Otwell and Nicolle Rager Fuller

Hubble died of a heart attack in 1953. One last small oddity awaited him. For reasons cloaked in mystery, his wife declined to have a funeral and never revealed what she did with his body. Half a century later the whereabouts of the century’s greatest astronomer remain unknown.

For a memorial, you must look to the sky and the Hubble Space Telescope, launched in 1990 and named in his honor.
—  Bill Bryson
MSH 11-62 and G327.1-1.1: Supernova Shock Waves, Neutron Stars, and Lobsters
  • Two new Chandra images of supernova remnants reveal intricate structures left behind after massive stars exploded.
  • Powerful winds of high-energy particles are released from the dense core of the dead star to create so-called pulsar wind nebulas.

  • MSH 11-62 and G327.1-1.1 are examples of how complex the aftermath of stellar explosions can be.

supernova that signals the death of a massive star sends titanic shock waves rumbling through interstellar space. An ultra-dense neutron star is usually left behind, which is far from dead, as it spews out a blizzard of high-energy particles. Two new images from NASA’s Chandra X-ray Observatory provide fascinating views - including an enigmatic lobster-like feature - of the complex aftermath of a supernova.

When a massive star runs out of fuel resulting in a supernova explosion, the central regions usually collapse to form a neutron star. The energy generated by the formation of the neutron star triggers a supernova. As the outward-moving shock wave sweeps up interstellar gas, a reverse shock wave is driven inward, heating the stellar ejecta.

Meanwhile, the rapid rotation and intense magnetic field of the neutron star, a.k.a. a pulsar, combine to generate a powerful wind of high-energy particles. This so-called pulsar wind nebula can glow brightly in X-rays and radio waves.

A long observation with Chandra of the supernova remnant MSH 11-62 (left image) reveals an irregular shell of hot gas, shown in red, surrounding an extended nebula of high energy X-rays, shown in blue. Even though scientists have yet to detect any pulsations from the central object within MSH 11-62, the structure around it has many of the same characteristics as other pulsar wind nebulas. The reverse shock and other, secondary shocks within MSH 11-62 appear to have begun to crush the pulsar wind nebula, possibly contributing to its elongated shape. (Note: the orientation of this image has been rotated by 24 degrees so that north is pointed to the upper left.)

MSH 11-62 is located about 16,000 light years from Earth. The foreground of MSH 11-62 is speckled with hundreds of sources associated with the open stellar cluster Trumpler 18, located at a distance of about 5,000 light years, revealing a vast collection of stars.

The supernova remnant G327.1-1.1, located about 29,000 light years from Earth, is another spectacular debris field left behind when a massive star exploded. The Chandra image of G327.1-1.1 (right image) shows the outward-moving, or forward, shock wave (seen as the faint red color), and a bright pulsar wind nebula (blue). The pulsar wind nebula appears to have been distorted by the combined action of the reverse shock wave, which may have flattened it, and by the motion of the pulsar, which created a comet, or lobster-like tail. An asymmetric supernova explosion may have given a recoil kick to the pulsar, causing it to move rapidly and drag the pulsar wind nebula along with it.

Two structures resembling lobster claws protrude from near the head of the pulsar wind nebula. The origin of these features, which may be produced by the interaction of the pulsar wind with the reverse shock, is unknown.

These results are presented at the “15 Years of Chandra” symposium (http://cxc.harvard.edu/symposium_2014/) by Patrick Slane of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., and Tea Temim of NASA’s Goddard Space Flight Center, Greenbelt, Md.

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

Image Credit: NASA/CXC/GSFC/T.Temim et al.; NASA/CXC/SAO/P.Slane et al

New Crew Arrives at Space Station to Continue Scientific Research

Three new crew members representing the United States, Russia and Italy are at the International Space Station (ISS). The Soyuz TMA-15M vehicle docked to the International Space Station at 9:48 p.m. EST, above the Pacific Ocean, approaching the coast of Ecuador.

Terry Virts of NASA, Soyuz Commander Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos) and Samantha Cristoforetti of the European Space Agency launched from the Baikonur Cosmodrome in Kazakhstan about six hours earlier at 4:01 p.m. (3:01 a.m. Monday in Baikonur).

Hatches between the two spacecraft are scheduled to open at about 11:30 p.m., with NASA Television coverage starting at 11 p.m.

The arrival of Virts, Shkaplerov and Cristoforetti returns the space station’s crew complement to six. The three join Expedition 42 Commander Barry Wilmore of NASA, as well as Flight Engineers Alexander Samokutyaev and Elena Serova of Roscosmos. They have been aboard the station since September.

The crew members will be working off the Earth, for the Earth conducting hundreds of scientific investigations and technology demonstrations during their six-month sojourn on the orbiting laboratory. These include observations of the genetic makeup of roundworms, examining aerosols in the atmosphere and levitating cooling liquid metals.

One new investigation will look at epigenetics, which means “outside the genes,” or changes that can be inherited for several generations without affecting an organism’s basic DNA. This Japan Aerospace Exploration Agency study may help determine whether the effects of microgravity are transmitted from one cell generation to another without changing the basic DNA of an organism. Researchers study millimeter-long roundworms, C. elegans, as models for larger organisms. In this investigation, four generations of the worms will be grown aboard the space station, with adults from each generation preserved for later study on Earth.

Continue Reading.

NASA’s Swift Mission Probes an Exotic Object: ‘Kicked’ Black Hole or Mega Star?

By Francis Reddy

An international team of researchers analyzing decades of observations from many facilities, including NASA’s Swift satellite, has discovered an unusual source of light in a galaxy some 90 million light-years away.

The object’s curious properties make it a good match for a supermassive black hole ejected from its home galaxy after merging with another giant black hole. But astronomers can’t yet rule out an alternative possibility. The source, called SDSS1133, may be the remnant of a massive star that erupted for a record period of time before destroying itself in a supernova explosion.

Continue Reading

NASA Astronomy Picture of the Day 2014 November 23

Tornado and Rainbow Over Kansas

The scene might have been considered serene if it weren’t for the tornado. During 2004 in Kansas, storm chaser Eric Nguyen photographed this budding twister in a different light — the light of a rainbow. Featured here, a white tornado cloud descends from a dark storm cloud. The Sun, peeking through a clear patch of sky to the left, illuminates some buildings in the foreground. Sunlight reflects off raindrops to form a rainbow. By coincidence, the tornado appears to end right over the rainbow. Streaks in the image are hail being swept about by the high swirling winds. Over 1,000 tornadoes, the most violent type of storm known, occur on Earth every year, many in tornado alley. If you see a tornado while driving, do not try to outrun it — park your car safely, go to a storm cellar, or crouch under steps in a basement.