Most Extreme Space Discoveries of
2012
by Elizabeth
Howell, SPACE.com Contributor
Astronomical
discoveries in 2012 have reshaped what we know about the universe and pushed
some instruments to the very limits of their observing power. Scientists
discovered a galaxy that harbors an enormous central black hole 17 billion times more massive than the
sun. Another research group spotted a scorching-hot rocky planet in the closest
star system to our own. Meanwhile, the records for most massive galaxy cluster
and most distant galaxy were shattered.
Here's a brief
rundown of some of the year's most extreme and exciting cosmic finds.
Most monstrous
black hole
Observers
probably don't want to get too close to NGC 1277 or its supermassive black hole, which takes up a
large portion of the galaxy itself. The central black hole is 17 billion times
more massive than the sun and makes up 14 percent of its host galaxy's mass,
compared to the usual 0.1 percent.
Researchers
were so flummoxed by the black hole's size that they took an extra year to
double-check their calculations before publishing their results.
Closest
exoplanet to Earth
In a surprise
discovery, astronomers found a planet that is about the same size as Earthin
the star system next door. The rocky planet was found in Alpha Centauri, a
three-star system just 4.3 light years from us.
Life is very
unlikely on this world. Its rocky surface may be molten, since the planet
orbits just 3.6 million miles (6 million kilometers) from its sun-like star.
(Earth, for comparison, circles 93 million miles, or 150 million km, from the
sun).
Alpha Centauri
Bb, as the planet is known, was discovered through tracking gravitational
wobbles around its planet star. The wobbles in this case are very subtle,
making the star move back and forth at no more than 1.1 mph (1.8 kph). The
research team stated it "pushed our technique to the limit," and some
astronomers are skeptical that the planet even exists.
And just this
month, a different research team detected five potential planets orbiting the
star Tau Ceti, which lies only 11.9 light-years from Earth. One of the newly
spotted candidate worlds may be capable of supporting life as we know it,
scientists say.
Smallest alien
worlds
Astronomers
using NASA's Kepler Space Telescope discovered three tiny planets 120 light-years
away from Earth. Circling the star KOI-961, the smallest of the three planets
is about the size of Mars, and all are smaller than Earth. Even the star itself
is tiny — just 70 percent larger than Jupiter.
"This is
the most compact system of planets," said John Johnson, of the California
Institute of Technology
in Pasadena. "It's like you have a shrink raygun and set it to seven times
smaller and zapped a planetary system."
Smallest solar
system
KOI-500 has five planets so crowded together that their
gravity jostles each other profoundly during their orbits. Their
"years" are only 1, 3, 4.6, 7.1 and 9.5 days long. Furthermore, the
planets are tiny: just 1.3 to 2.6 times the size of Earth. All of this
action takes place in an area 150 times smaller than Earth's orbit, astronomers
said.
"At this
rate, you could easily pack in 10 more planets, and they would still all fit
comfortably inside the Earth's orbit," Darin Ragozzine, a planetary
scientist at the University of Florida at Gainesville, said in a statement.
Most distant
galaxy
Much like
the 100-meter dash world record, the record for farthest known galaxy often changes. The newest
potential record-holderis UDFj-39546284, which had taken shape when the
universe was only 380 million years old. Its extreme age was discovered in 2012
using new observations from NASA's Hubble Space Telescope.
The galaxy is
part of a group of seven that astronomers examined, forming perhaps the first
reliable observations of galaxies that formed 400 million and 600 million years
after the Big Bang created the universe 13.7 billion years ago. [Gallery: Spectacular Hubble Photos]
Oldest, most
distant supernovas
In 2012,
astronomers described what they think led to the oldest, most distant supernovas in the universe.
Scientists believe some of these "super-luminous" supernovas come
from massive stars — 100 to 250 times the mass of the sun — that explode and
blast their matter into space.
Astronomers
stated that inside these massive stars, gamma-ray light changes into electron
pairs as well as antimatter positrons. The gamma rays usually stop the star
from collapsing due to gravity, but the grip weakens as gamma rays convert to
matter. It is at this point that the star implodes, sparking the explosion.
Most massive
galaxy cluster
At 2,000 times
more massive than the Milky Way, a large cluster of galaxies some 7 billion
light-years away dwarfs just about any other collection of matter known.
Astronomers say the cluster — properly known as SPT-CLJ2344-4243and
dubbed the Phoenix cluster — appears to contain
thousands of galaxies of many different sizes.
Astronomers
first spotted the Phoenix cluster in 2010, but didn't realize its extent until
they did follow-up observations with NASA's Chandra X-ray Observatory.
High-energy light pouring out of the cluster make it the most X-ray luminous
one ever found, at 35 percent brighter than the last record-holder found.
Biggest map of
the universe
Courtesy of a
mega map, astronomers are a step closer to understanding how the universe came
to be. The Sloan Digital Sky Survey III released a map that charts more than 1
million galaxies in a total volume of 70 billion cubic light-years.
The map could
help astronomers better understand the mysterious dark matter and dark energy
that appears to make up most of the universe, researchers said.
Deepest view of
the universe
The Hubble
Space Telescope is peering back further and further in time. The famous
orbiting observatory captured light that emanated 13.2 billion years ago, when
the universe was just 500 million years old or so.
Hubble's
picture, which is called the eXtreme Deep Field, shows galaxies and starlight
accumulated over 10 years in a small bit of sky; this is the best method we
have to see objects so far away. The photo is a successor to Hubble's
"Ultra Deep Field", which the telescope took in 2003 and 2004. [Video: Hubble's eXtreme Deep Field]
Most magnetic
star
There's a star
20,000 light-years from Earth with a real magnetic personality. NGC 1624-2,
which is about 35 times as massive as our sun, was spotted in the constellation
Perseus. With a magnetic field 20,000 times stronger than the sun's—
and 10 times more powerful than that of any known star — NGC 1624-2 drags a
blanket of trapped charged particles around it.
"Magnetic
fields of this strength are extremely rare; they are only known to exist in a
few other stars of much lower mass," study lead author Gregg Wade, an
astronomer at the Royal Military College of Canada, told SPACE.com in a
September interview. "To find such a strong field is very lucky."
X-ray blast in
the universe's youth
A jet of X-rays
emanating from quasar GB 1428 — a galaxy that has a huge black hole in its
center — was found about 12.4 billion light-years from Earth. The
radiation band is estimated at about twice the diameter of the Milky Way.
With the
previous record-holder at 12.2 billion light-years away, astronomers said they
are getting more information on how black holes behaved in the universe's early
days.
Biggest core
found in a ginormous galaxy
Lurking in a
galaxy about 10 times the width of the Milky Way lies a large, diverse galactic core that doesn't seem to
have a black hole associated with it.
The wispy core
of A2261-BCG, which is about 10,000 light-years across, puzzles astronomers
because supermassive black holes are expected to be at the heart of most
galaxies. Hubble Space Telescope observations suggest the core might have been
constructed when two galaxies merged.