December 22, 2012, was a good day for some; this is because the world is still standing and did not come to an end the day before as some doomsday prophecies have theorized. However, while Dec 21 may have passed without incident, this does not mean mankind is out of the woods yet. Letting our guards down may be a little bit premature as astronomers have detected an asteroid heading right for Earth.
The asteroid is estimated to be about 140 meters and was discovered by scientists from the University of Hawaii. While the asteroid will just barely miss our planet by about 890,000 kilometers, the fact that a behemoth rock is able to come that close is reasonable cause for alarm.
The reason we should worry is because that very same asteroid could change course and be headed back at Earth’s direction in the year 2040. This is due to a phenomenon known as the Yarkovsky effect. The effect occurs when an asteroid absorbs energy from the sun, which can alter the original direction of the object’s trajectory.
The asteroid in question is relatively the same mass as the one that slammed into an uninhabited area of Siberia in 1908, which caused an impact comparable to that of 1,000 atomic bombs going off at once.
Most astronomers agree that being hit by an asteroid is not a matter of “if” but “when.” For this reason, The B612 Foundation, a California based organization, is in the process of obtaining a half billion dollar fund for an infrared space telescope that is capable of detecting large celestial rocks that may pose a threat to Earth.
The telescope they hope to produce is called the Sentinel and will orbit the planet and take pictures of the sky and relay it back home. Detection is the key because we cannot stop what we don’t see. It is estimated that the Sentinel will be able to capture the locations of about 10,000 new asteroids every month.
The astronomy community is in shock and delight as a new discovery may completely change the current theory about the evolution of our solar system.
It is common knowledge that the sun is about 4.6 billion years old. At the time it was forming, it was surrounded by a cloud of dust and gas, which would ultimately become the building blocks for the billions of asteroids that circle the solar system today.
Current theories propose that two early types of solids were formed eons apart. However, astronomers from the University of Copenhagen have devised a new dating technique that puts this belief into question.
The two types of solids in question are chondrules and calcium-aluminum-rich inclusions (CAIs), both of which are commonly found in meteorites. CAIs form when droplets of molten gas reach less than 1,880 degrees Fahrenheit. Chondrules, on the other hand, are formed when large collections of dust drop in temperatures below 1,340 degrees Fahrenheit.
The new model proposes that the spinning disk responsible for the creation of the sun, planets and moons had massive amounts of energy within it. This caused particles to flatten as the center of the disk was formed into the sun. As the material began condensing and collapsing, gigantic surges in energy caused a massive wave of heat that affected the state of the chondrules and CAIs.
The discovery could explain how all solids are formed within a protoplanetary disk. Previous models show that within our solar system, chondrules did not form for another two million years until after the formation of CAIs. This theory, however, puzzled astronomers as observation of other planetary systems suggest they were formed differently.
Old dating methods rely on the amount of aluminum found in meteorites. This method was flawed because not all forms of aluminum are distributed evenly within the solar system. Under the new dating system, meteorites are broken apart where the lead and uranium can be measured using spectrometers.
According to NASA a newly discovered asteroid will experience a close encounter with Earth this coming Monday; but worry not – it will not spell disaster.
NASA’s Near-Earth Object Program Office contends that the small space rock – called 2011 MD – will pass 7,500 miles over Earth’s surface over the southern Atlantic Ocean.
While it will come close, it is not a distance record holder. Earlier in the year, a tiny asteroid flew by even closer; that is within 3,400 miles of the Blue Planet.
The last asteroid measures 33 feet long and was discovered with New Mexican telescopes. Scientists say that asteroids this size can sail past Earth every six years.
The asteroid will briefly be seen rather brightly; well, that is bright enough such that medium-size telescopes may be able to spot it.
The new ultra-powerful Hubble Space Telescope found yesterday a galaxy whose light traveled more than 13 billion light-years to get to earth, making it the oldest astronomical object ever discovered.
A title previously held by a gamma-ray burst, UDFy-38135539, formed within 600 million years of the universe’s creation, 14 billion years ago.
“I don’t think this is the limit, perhaps not even that close to it,”
Said lead researcher Matthew Lehnert, with France’s Observatoire de Paris,
“UDFy-38135539 was already a challenge and perhaps we won’t be able to do much better than it for a while yet.”
The term “Redshift” refers to what happens when light coming from an object is shifted to appear redder. The universe today is redshift 0. Redshift 1 refers to when the universe was half its present age.
“Redshift 8.6 is likely to be about as high as we can reach with the current generation of telescopes,”
Said astrophysicist Michele Trenti of the University of Colorado in Boulder.
“With the Hubble Space Telescope it might be possible to find some galaxies up to redshift 10, but these objects are expected to be very rare and extremely faint.”
Verification of a galaxy within 600 million light-years of the Big Bang is exceptionally interesting to scientists because its during this time that radiation from the first objects in the universe stripped off electrons from hydrogen atoms created during the Big Bang.
“It’s quite amazing to me that humble, small galaxies — the ones that likely existed at this high redshifts, early in the history of the universe — could literally change its overall state,”
“It raises the question what are these other sources and are they like UDFy-38135539 or not? We know from the (Hubble Ultra Deep Field) images that whatever they are, they are not detected in those images. We need more data and much deeper data.”
Sky watchers from Asia and North America too – you’re in for a great galactic treat!
During the pre-dawn hours of Tuesday, the annual Leonid meteor shower will light up the sky with delight for the eye. This year it should be visible to anyone who lives in the Northern Hemisphere.
The Leonids are created by the comet Swift-Tuttle, which makes its way through the inner solar system every 33 years on its orbit around the sun. Each time by, it leaves a new river of debris, mostly tiny bits of ice and rock. Over time, the cosmic streams spread out, so pin-pointing the exact effect which it causes is next to impossible.
When Earth plows into the debris, the debris hits the atmosphere and vaporizes. This sometimes creates wonderful streams of light and even an occasional fireball with a smoky trail.
The Leonid stream is moving in the opposite direction of Earth, producing impact speeds of 160,000 mph (72 kilometers per second). This is higher than many other meteors. The meteor shower can appear anywhere, however they all point to a hub, or radiant in the Leo constellation. This is where the name Leonid derives from.
The best way to view the show will be by catching it in a rural area, where there are few lights and buildings and traffic.