'Potential city killer' asteroid with an orbiting moon flies near Earth

The 1998 QE2 asteroid, 2.7 km in diameter and dubbed a “potential city killer,” with its own moon rotating around it, will pass Earth on Friday, giving astronomers the only opportunity for at least the next two centuries to observe the celestial body.

The asteroid will pass Earth closer than ever before in
astronomical terms – just 5.8 million kilometers or
about 15 times the distance between Earth and the moon – 
giving a unique opportunity for astronomers to learn as much as
possible about it.

Radar observations led by scientist Marina Brozovic of NASA’s Jet
Propulsion Laboratory revealed a surprising fact about the
asteroid when it was about 6 million kilometers from Earth. Using
a 70-meter Deep Space Network antenna at Goldstone, California
NASA detected a moon that was rotating around it. These binary or
triple systems make up about 16 percent of asteroids in the
near-Earth population. The diameter of the asteroid’s satellite
was estimated at approximately 600 meters and the rotation period
of less than four hours.

In comparison, the Chelyabinsk meteorite that hit Russia in
February, injuring more than 1,500 people, was about 20 meters.
While the 1908 Tunguska meteoroid was estimated at about 100
meters as the explosion it produced was recognized to have been
the largest impact event on or near Earth in recorded history.

Events in Russia in February have triggered debate about the
threat our civilization faces from asteroids.

“An asteroid that size, a kilometer or bigger, could plausibly
end civilization,”
John Holdren, a White House science
advisor, told legislators at a US House of Representatives
Science Committee hearing in May. However only about 10 percent
of an estimated 10,000 potential “city-killer” asteroids,
those with a diameter of about 50 meters, have been found,
Holdren added.

The closest approach of the asteroid is on Friday
at 20:59 GMT, however the best time to observe the
celestial projectile will be the first week of June, when the
asteroid enters the Earth’s northern skies. At that time it will
turn its sunlit side towards our planet. 

First radar images of asteroid 1998 QE2 were obtained when the asteroid was about 3.75 million miles (6 million kilometers) from Earth. The small white dot at lower right is the moon, or satellite, orbiting asteroid 1998 QE2. Image credit: NASA/JPL-Caltech/GSSR

NASA says that it will be visible through a usual backyard
telescope despite its relative distance from Earth. At maximum
brightness on June 3 and 4 it is expected to shine as an 11th
magnitude star.

The 1998 QE2 will only pass earth again in the next two
centuries, so scientists won’t get another such opportunity to
study it.

NASA plans to exploit radars to reveal the alien
landscape that no one has ever seen before.

“It is tremendously exciting to see detailed images of this
asteroid for the first time,”
said radar astronomer Lance
Benner, the principal investigator for the Goldstone radar
observations from NASA’s Jet Propulsion Laboratory in Pasadena,
California.

Aside from monitoring potential threats, radar observations allow
the opportunity to learn more about the origins of our solar
system, the source of water on Earth, and even the origin of
organic molecules that lead to the development of life, says
NASA.

“With radar we can transform an object from a point of light
into a small world with its own unique set of characteristics. In
a real sense, radar imaging of near-Earth asteroids is a
fundamental form of exploring a whole class of solar system
objects,”
acknowledged Benner.

Another thing that intrigues scientists is the asteroid’s dark
complexion. According to the measurements of the
Spitzer space telescope QE2 reflects only 6 percent of the light
that falls on it, which makes it blacker than coal. Benner says
it makes QE2 similar to a carbon rich 101955 Bennu
asteroid, adding that the latter can harbor amino acids and other
organic molecules essential to primitive life.

The asteroid 1998 QE2 was discovered on August 19, 1998, by the
Massachusetts Institute of Technology Lincoln Near Earth Asteroid
Research (LINEAR) program near Socorro, New Mexico. The
asteroid is believed to be nine-Queen Elizabeth II
ship-lengths in size but it is not named after the
transatlantic-crossing flagship. Instead, the name is assigned by
the NASA-supported Minor Planet Center in Cambridge,
Massachusetts, which “gives each newly discovered asteroid a
provisional designation starting with the year of first
detection, along with an alphanumeric code indicating the
half-month it was discovered, and the sequence within that
half-month.”

While NASA is tracking about 95 per cent of the largest objects
flying near Earth, scientists are trying to find ways to
eliminate the potential threat of one of the celestial bodies
hitting our planet.

Following the Chelyabinsk meteor strike, the European Space
Agency (ESA) announced a joint Asteroid impact and Deflection
Assessment mission (AIDA) between Europe and the US that aims to
strike an asteroid with a spacecraft.

This article originally appeared on: RT