|
Pluto’s Fourth Moon Discovered
NASA discovered a fourth moon revolving around the icy planet, Pluto. The fourth moon, named P4 for
now was discovered by the Hubble space telescope. P4 is said to be the
smallest moon measuring just 21 miles in diameter. The largest moon, Charon is some 648 miles in diameter.
The discovery of P4 was the result of work being done to support NASA's
$700-million New Horizons mission, which aims to send a probe through
the Pluto system in 2015. Pluto's fourth moon was spotted while Hubble
was being used to search for rings around the dwarf planet, scientists said.
"This is a fantastic discovery," said Alan Stern of the Southwest
Research Institute in Boulder, Calif., principal investigator on the New
Horizons mission. "Now that we know there's another moon in the Pluto
system, we can plan close-up observations of it during our flyby."
Scientists first spotted P4 in a photo taken with Hubble's Wide Field
Camera 3 on June 28, 2011 the STSI statement said. Its existence was
confirmed in two more pictures taken on July 3 and July 18. It may also
appear as "a very faint smudge" in Hubble images from 2006, according to the statement.
P4 is located between the orbits of Nix and Hydra, according to the STSI statement.
All four of Pluto's moons are believed to have formed when Pluto and
another planet-sized body collided in the early history of our solar
system. Earth's Moon may have formed the same way
This is great news for NASA, as one of their latest missions New
Horizons is scheduled to pass by Pluto in 2015. Scientists believe that
the moons revolving Pluto were formed by a collision of some foreign
object with the planet. The moon, P4 was first detected by one of Hubble’s Wide Field cameras on 28th June, 2011.
Planet Pluto
Pluto and its moons are roughly some 5 million miles away.
Pluto cast an extremely long shadow: it has an average distance of 5.9
billion miles (9.495 billion km) from the Sun, compared to Earth's
distance of 93 million miles (149.7 million km).
In June 2011, Pluto came between a star and Earth, casting a small shadow on
Earth's surface that astronomers tracked across the Pacific. This event, known as an occultation, occurred on June 23, according to
scientists at Lowell Observatory in Arizona. Four of them traveled on a
modified 747 aircraft that carried a big telescope, which managed to
snap images of Pluto and its thin atmosphere. |
|
|
