Color-Shifting Asteroid Observed For The First Time In Real-Time

Eddie Gonzales Jr. – MessageToEagle.com – A strange behavior of an asteroid in the act of changing color from red to blue was observed by MIT astronomers. The asteroid is likely shedding reddish dust, revealing a fresh, blue surface beneath.

Astronomers discovered an “active” asteroid within the asteroid belt, sandwiched between the orbits of Mars and Jupiter.

 The asteroid 6478 Gault is seen with the NASA/ESA Hubble Space Telescope, showing two narrow, comet-like tails of debris that tell us that the asteroid is slowly undergoing self-destruction. The bright streaks surrounding the asteroid are background stars. The Gault asteroid is located between the orbits of Mars and Jupiter. Image: NASA, ESA, K. Meech and J. Kleyna, O. HainautThe asteroid 6478 Gault is seen with the NASA/ESA Hubble Space Telescope, showing two narrow, comet-like tails of debris that tell us that the asteroid is slowly undergoing self-destruction. The bright streaks surrounding the asteroid are background stars. The Gault asteroid is located between the orbits of Mars and Jupiter. Image: NASA, ESA, K. Meech and J. Kleyna, O. Hainaut

The space rock, designated by astronomers as 6478 Gault, appeared to be leaving two trails of dust in its wake — active behavior that is associated with comets but rarely seen in asteroids.

“That was a very big surprise,” says Michael Marsset, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS), said in a press release.

“We think we have witnessed the asteroid losing its reddish dust to space, and we are seeing the asteroid’s underlying, fresh blue layers.”

Astronomers first discovered 6478 Gault in 1988 and named the asteroid after planetary geologist Donald Gault. Until recently, the space rock was seen as relatively average, measuring about 2.5 miles wide and orbiting along with millions of other bits of rock and dust within the inner region of the asteroid belt, 214 million miles from the sun.

The team observed the asteroid using NASA’s Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. They determined that the asteroid s a dry, rocky body; its surface is composed mainly of silicate, a dry, rocky material, similar to most other asteroids, and, more importantly, not at all like most comets.

The team and other groups studying 6478 Gault believe the reason for the color shift, and the asteroid’s comet-like activity is likely due to a fast spin. The asteroid may be spinning fast enough to whip off layers of dust from its surface, through sheer centrifugal force. The researchers estimate it would need to have about a two-hour rotation period, spinning around every couple of hours, versus Earth’s 24-hour period.

“About 10 percent of asteroids spin very fast, meaning with a two- to three-hour rotation period, and it’s most likely due to the sun spinning them up,” says Marsset.

This spinning phenomenon is known as the YORP effect (or, the Yarkovsky-O’Keefe-Radzievskii-Paddack effect). Astronomers have observed the YORP effect on a handful of asteroids in the past.

Further study of this asteroid will be continued.

Paper

Written by Eddie Gonzales Jr. – MessageToEagle.com Staff