Two new moons found orbiting Uranus

Scientists have discovered two new moons orbiting the planet Uranus, after re-examining data captured by the Nasa space probe Voyager 2 in 1986 found evidence of the small, dark "moonlets" lurking behind the large gas planet and making "waves" in its closest rings.

27 moons are already known to orbit Uranus, which is the third biggest planet in our solar system, but the two new ones appear to be nearer to the ice giant than any others. Little is known about Uranus, which is 20 times further from the sun than Earth is and smaller than similar ringed, gas planets Jupiter and Saturn. Jupiter and Saturn are also closer to earth, which has made them easier to investigate. They have 67 and 62 moons respectively.

A lot of the information scientists have at their disposal was gathered by Voyager 2, which flew by 30 years ago, nine years after it was launched in 1977. However, two planetary scientists from the University of Idaho’s Moscow campus, Rob Chancia and Matthew Hedman, have used the old data to show there are wavy patterns in two of Uranus' 13 rings, called Alpha and Beta, consistent with the pulls of two little moons. They also suggested the moons are so tiny and dark - meaning they do not reflect light - they were written off as background noise by the spacecraft.

Analysis of numerical data gathered by Voyager 2 showed similar patterns in the Alpha and Beta rings to those caused by the pull of some of Uranus' other moons, such as Cordelia and Ophelia. The scientists predict if these two new moons exist they would each measure between two and nine miles across.

The discovery is not yet confirmed and the researchers are still in the process of publishing in a peer-reviewed journal. Mark Showalter from the Search for Extraterrestrial Intelligence (SETI) Institute in California, who has previously discovered moons around Uranus, told New Scientist the existence of the two new moons is "certainly a very plausible possibility".

To read more, click here.

Picture courtesy: Mail Online

Astronomers find the 'roundest' star in the universe

Stars are not perfect spheres. While they rotate, they become flat due to the centrifugal force. Researchers around Laurent Gizon from the Max Planck Institute for Solar System Research and the University of Göttingen have succeeded in measuring the oblateness of a slowly rotating star with unprecedented precision.

The researchers have determined stellar oblateness using asteroseismology - the study of the oscillations of stars. The technique is applied to a star 5000 light years away from Earth and revealed that the difference between the equatorial and polar radii of the star is only 3 kilometers - a number that is astonishing small compared to the star's mean radius of 1.5 million kilometers; which means that the gas sphere is astonishingly round.

All stars rotate and are therefore flattened by the centrifugal force. The faster the rotation, the more oblate the star becomes. Our Sun rotates with a period of 27 days and has a radius at the equator that is 10 km larger than at the poles; for the Earth this difference is 21 km. Gizon and his colleagues selected a slowly rotating star named Kepler 11145123. This hot and luminous star is more than twice the size of the Sun and rotates three times more slowly than the Sun. The periodic expansions and contractions of the star can be detected in the fluctuations in brightness of the star.

To read more about the research and other findings, click here.

Pluto's heart-shaped feature hints at subsurface ocean

New research by astronomers suggests that Pluto's famous heart-shaped feature caused the dwarf planet to roll over the eons, and this reorientation probably wouldn't have been possible without a subsurface ocean.

The cutaway image of Pluto shown here is a section through the area of Sputnik Planitia, with dark blue representing a subsurface ocean and light blue for the frozen crust.

The left lobe of Pluto's "heart" is a 600-mile-wide (1,000 kilometers) plain called Sputnik Planitia (formerly known as Sputnik Planum), which astronomers think is an enormous impact crater. This basin has been filling with nitrogen ice over the years and now contains huge amounts of the stuff. y NASA's New Horizons spacecraft's observations, which flew by Pluto last year, also suggest that Sputnik Planitia's ice may be up to 6 miles (10 km) thick.

Sputnik Planitia is aligned nicely with Pluto's "tidal axis" — the line along which the gravitational pull from the dwarf planet's largest moon, Charon, is said to be the strongest.

If Pluto does have an ocean, how has it managed to avoid freezing up entirely over the past 4.5 billion years? Pluto is big enough that it may have retained a substantial amount of internal heat, Nimmo said. And the dwarf planet's water may contain significant amounts of ammonia or other substances that act as an antifreeze, he added.

Astronomers think subsurface oceans exist on the Saturn moons Enceladus and Titan; the Jovian satellites Europa, Ganymede and Callisto; and a number of other solar system bodies. Such buried water may be abundant in the Kuiper Belt, the ring of frigid objects beyond Neptune's orbit.

To read more or watch a video on the same, click here.

Photo credit: Pam Engebretson

Two colliding spiral galaxies produce rare eyelid-shaped formations

Using the Atacama Large Millimeter/submillimeter Array (ALMA), a high-resolution telescope in the Chilean Andes, astronomers have discovered a rare star formation. The structure, which looks remarkably like two eyelids, was produced by the grazing collision of two spiral galaxies. Far beyond our galaxy, a swirling stellar tsunami has created a pair of watchful cosmic eyes.

Lead author Michele Kaufman, an astronomer formerly with The Ohio State University in Columbus, said, “Finding one in such a newly formed state gives us an exceptional opportunity to study what happens when one galaxy grazes another.”

When IC 2163’s outer arm clipped NGC 2207’s spinning disk, the collision produced brilliant formations of stars, dust, and gas. Kaufman and colleagues spotted the two spiral galaxies some 114 million light-years from Earth, utilizing ALMA’s high sensitivity and resolution to track the movement of carbon monoxide gas at the intersection of the two.

New research suggests that gas from IC 2163’s outer “eyelid” is spiraling inward at over 100 kilometers per second. But the gas slows down as it approaches the center, and begins to follow the normal rotation of the galaxy.

To read more about the research, click here.

November full moon to be the closest, biggest and brightest in decades!

Sky watchers and moon lovers will be getting to a rare astronomical treat on November 14. So you may want to mark the date on your calendar.

NASA says, the full moon will be the closest moon to date in the twenty-first century, on November 14. The full moon coming up this month will not only be a “supermoon” but also be the biggest supermoon to grace our skies in decades.

Our full moon will be 14 percent bigger and 30 percent brighter than usual, according to NASA. This will make it the biggest “supermoon” in almost 70 years! You can watch the You Tube video here in which NASA explains how it is the biggest.

This month, the full moon reaches complete fullness at 8:52 a.m. on Nov. 14, which means the moon might actually appear brighter and fuller the evening of Nov. 13 rather than the 14th. The moon will begin to rise at 5:13 p.m. on Nov. 13, just seven minutes before sunset. It will be completely dark that evening by 5:51 p.m.

A moon is considered a “supermoon” when it passes slightly closer to Earth in its orbit. According to NASA, “full moons vary in size because of the oval shape of the Moon’s orbit. It is an ellipse with one side (perigee) about 50,000 km closer to Earth than the other (apogee).”

This year’s pass will be especially close, making the moon appear extra-spectacular. A “closer than usual” pass to the Earth can happen even when the moon isn’t full, but the effect is much more noticeable when it is.

The next time the moon will be so close, full and bright is in 2034, November 25, 2034, to be precise.

The next supermoon will be visible on Dec. 14, and is expected to wipe out the view of the geminid meteor shower.

To read more and see more photos, click here 

You can watch the You Tube video here