On October 9th, the Juno spacecraft had a rare opportunity. Traveling about twice as fast as a typical satellite, it had a unique view of the Earth-moon system. The result was an intriguing, low-resolution glimpse of what our world would look like to a visitor from afar.
NASA’s Wide-field Infrared Survey Explorer (WISE), an infrared space telescope, mapped the asteroid population near Earth and elsewhere in the solar system. The asteroid survey, which NASA says is the most accurate ever performed, also lowered the estimated number of giant near-Earth asteroids — space rocks the size of a mountain or larger — from 1,000 to 981, with about 911 of those already known, researchers said.
By the end of the WISE telescope’s extended mission, called NEOWISE, last year, astronomers had found 90 percent of the largest asteroids near our planet, NASA scientists said, which met the goal that was set forth by Congress in 1998.
The WISE space telescope mapped the entire sky twice between January 2010 and February 2011, surveying near-Earth asteroids, brown dwarfs, galaxies and other deep space objects in infrared light. As part of its near-Earth asteroid search, the space observatory scanned for space rocks that orbited within 120 million miles (195 million kilometers) of the sun. The Earth is about 93 million miles (150 million km) from the sun. [Video: Killer Asteroids, We’re WISE to You .Now
Flights of Fancy, this is what I call about the Modern Astronomical Theories, and even Astrophysics.
It has been believed that ,in Science, Scientists observe some phenomenon, find some more similar phenomenon, formulate a Theory, check with all available material and verify the Theory and announce it.
Not any more!
People find something which they do not understand yet, they publish it as an Axiom!
With the present Laws of Astrophysics and Physics, it should not be there.there, it should not Exist.
But IT IS!
TW Hydrae, a star located about 176 light years away, is one of the closest things in the universe we have to a time machine. That’s because it’s only about 8 million years old, and its believed to look a lot like what our own Solar System looked like in the first few million years of its existence. By studying TW Hydrae, astronomers can learn more about the history of our own Sun.
Recently, while observing this star, the Hubble Telescope found something pretty amazing – a gap in the star’s protoplanetary disk. The disk, which was discovered a few years ago, is an accretion of large amounts of material that are expected to coalesce into a planet over the course of time. The most likely reason why such a gap would exist would be theformation of the planet. As the planet traveled around the star, its gravity would either attract or push the disk material out of its way. Such a planet would be somewhere in between 6 to 28 times more massive than Earth.
If the gap really is where a planet is located, then that planet is 7.5 billion miles from its star. That’s about twice as far as Pluto’s distance from our own Sun, making this the planet that is furthest from its parent star that we know of.
Here’s the real kicker about this planet, though: if it’s there, then current astronomical theories about how planets form are at least partially wrong. Planets are expected to form slowly over time, accumulating more and more rock and dust as it travels through the protoplanetary disk. Because planets like this are so far out from their stars, their orbits are slower and there is less material available to form a planet. Given that, it should take about 200 million years for that planet to have formed – way more years than TW Hydrae has been around.
“Astronomers using ESO’s Very Large Telescope and the Canada-France-Hawaii Telescope have identified a body that is very probably a planet wandering through space without a parent star. This is the most exciting free-floating planet candidate so far and the closest such object to the Solar System at a distance of about 100 light-years. Its comparative proximity, and the absence of a bright star very close to it, has allowed the team to study its atmosphere in great detail. This object also gives astronomers a preview of the exoplanets that future instruments aim to image around stars other than the Sun.
Free-floating planets are planetary-mass objects that roam through space without any ties to a star. Possible examples of such objects have been found before , but without knowing their ages, it was not possible for astronomers to know whether they were really planets or brown dwarfs — “failed” stars that lack the bulk to trigger the reactions that make stars shine.
But astronomers have now discovered an object, labelled CFBDSIR2149 , that seems to be part of a nearby stream of young stars known as the AB Doradus Moving Group. The researchers found the object in observations from the Canada-France-Hawaii Telescope and harnessed the power of ESO’s Very Large Telescope to examine its properties .
The AB Doradus Moving Group is the closest such group to the Solar System. Its stars drift through space together and are thought to have formed at the same time. If the object is associated with this moving group — and hence it is a young object — it is possible to deduce much more about it, including its temperature, mass, and what its atmosphere is made of . There remains a small probability that the association with the moving group is by chance.
The link between the new object and the moving group is the vital clue that allows astronomers to find the age of the newly discovered object . This is the first isolated planetary mass object ever identified in a moving group, and the association with this group makes it the most interesting free-floating planet candidate identified so far. ”
While scientists have found objects they believe might be sunless planets in the past, they couldn’t say for certain whether such celestial objects were planets or brown dwarves (which are effectively failed stars). CFBDSIR2149 is the most conclusive such object yet, since it isn’t located anywhere near a bright star as far as the researchers can tell.
According to the researchers, this object is quite massive—it has 4 to 7 times the mass of Jupiter—and at 430 degrees Celsius (about 806 degrees Fahrenheit), it’s very warm (the ESO didn’t explain why CFBDSIR2149 may be so toasty, though). Also, they say, this maybe-planet is young in astronomical terms, at between 50 and 120 million years of age.'(techhive.com)