NASA Discovers Strange Object in Space
NASA & Scientists are Unable to Identify It
Mystery Object Spotted in Space
NASA & Scientists are Unable to Identify a Strange Object
NASA's Hubble Space Telescope has observed a mysterious
X-shaped debris pattern and trailing streamers of dust that suggest a
head-on collision between two asteroids. Astronomers have long thought
the asteroid belt is being ground down through collisions, but such a
smashup has never been seen before.
Asteroid collisions are
energetic, with an average impact speed of more than 11,000 miles per
hour, or five times faster than a rifle bullet. The comet-like object
imaged by Hubble, called P/2010 A2, was first discovered by the Lincoln
Near-Earth Asteroid Research, or LINEAR, program sky survey on Jan. 6th.
New Hubble images taken on Jan. 25th and 29th show a complex X-pattern of
filamentary structures near the nucleus.
Within less than a month of its discovery it was doubtful that the tail
of P/2010 A2 was generated via active outgassing from sublimation of
ices hidden beneath the crust. Early modeling indicated that the
asteroid became active in late March 2009, reached maximum activity in
early June 2009, and eased activity in early December 2009.
|Hubble shows the main nucleus of P/2010 A2 lies
outside its own halo of dust.
This has never been seen before in a
comet-like object. The nucleus is estimated to be 460 feet in diameter.
"This is quite different
from the smooth dust envelopes of normal comets," said principal
investigator David Jewitt of the University of California at Los
"The filaments are made of dust and gravel, presumably recently
thrown out of the nucleus. Some are swept back by radiation pressure
from sunlight to create straight dust streaks. Embedded in the filaments
are co-moving blobs of dust that likely originated from tiny unseen
comets fall into the inner regions of the solar system from icy
reservoirs in the Kuiper belt and Oort cloud.
As comets near the sun and
warm up, ice near the surface vaporizes and ejects material from the
solid comet nucleus via jets.
But P/2010 A2 may have a different origin.
It orbits in the warm, inner regions of the asteroid belt where its
nearest neighbors are dry rocky bodies lacking volatile materials.
The position of the nucleus was remarkable for being
offset from the axis of the tail and outside of the dust halo, a
situation never before seen in a comet. The tail is created by
millimeter sized particles being pushed back by solar radiation
P/2010 A2 was discovered on January 6th, 2010 by Lincoln
Near-Earth Asteroid Research (LINEAR) using a 1 meter (36") reflecting
telescope with a CCD camera.
It has been observed over a 112 day arc of
the 3.5 year orbit. It appears to have come to perihelion (closest
approach to the Sun) around the start of December 2009, about a month
before it was discovered.
With an aphelion (furthest distance from the Sun) of only 2.6 AU, P/2010
A2 spends all of its time inside of the frostline at 2.7 AU. Beyond the
frostline volatile ices are generally more common. Early observations
did not detect water vapor or other gases.
P/2010 A2 is a small Solar System body that displayed characteristics of both an asteroid and a comet, and thus, was initially given a cometary designation. Since it has the orbit of a main-belt asteroid and showed the tail of a comet, it was listed as a main-belt comet.
But within a month of discovery, analysis of images by the Hubble telescope suggested that its tail was generated by dust and gravel resulting from a recent head-on collision between asteroids rather than from sublimation of cometary ice.
Observations with the Hubble space telescope and the narrow angle camera on board the Rosetta spacecraft indicate that the dust trail seen was probably created by the impact of a small meter size object on the larger asteroid in February or March 2009. Though it can not be ruled out that the small asteroids rotation increased from solar radiation resulting in a loss of mass that formed a comet-like tail.
P/2010 A2 is likely about 150 meters (460 feet) in diameter. Even when it was discovered it was suspected of being less than 500 meters in diameter. Another object, centaur 60558 Echeclus in 2006, was suspected of outgassing as a result of an undetermined splitting event.
The orbit of P/2010 A2 is consistent with membership in the Flora asteroid family, produced by collisional shattering more than 100 million years ago. The Flora family of asteroids may be the source of the K/T impactor, the likely culprit in the extinction of the dinosaurs.