Gravity waves detected at last!

Scientists finally discover gravitational waves that were predicted a century ago.

A very special burst of waves from deep space has forever changed the way we look at the universe. These aren’t water waves or waves of light. They are gravity waves, tiny ripples produced by massive objects moving very quickly.

Two black holes produced the newly reported waves when they collided at some point roughly 1.3 billion years ago. Black holes are massive objects that trap light because their gravity is so strong.

Scientists announced the long-awaited discovery of these waves on February 11. That was a century after the famous physicist Albert Einstein first predicted gravity waves would exist. They are also describing their data in a paper published February 11 in Physical Review Letters. 

"It's the first time the universe has spoken to us through gravitational waves," LIGO laboratory executive director David Reitze said at a press conference February 11. "As we open a new window on astronomy, we may see things we never saw before."

Their discovery now gives scientists a new tool for studying the universe. Astronomers need these tools because not everything in the universe can be seen through a telescope. Stars, galaxies and other bright objects emit light that travels to Earth. But black holes are truly black. They don’t emit light, so telescopes can’t see them.

“Gravitational waves allow us to look at the universe not just with light but with gravity,” says Shane Larson. He’s an astrophysicist at Northwestern University in Evanston, Ill.

The discovery immediately becomes a likely candidate for a Nobel Prize. And that's not just because it ties a neat bow around decades of evidence supporting a major prediction by Einstein. In 1916, he came up with the idea for gravitational waves, also called gravity waves. He had just introduced his famous theory of general relativity. That theory says that objects with mass will curve space, similar to how a person standing on a trampoline will bend the fabric. The bending of space changes the motion of nearby objects. For example, the sun’s mass forces Earth to orbit the star in an ellipse, not just move in a straight line.

What can science tell us about the Star of Bethlehem?

During winter it can sometimes feel that the whole day passes in the blink of an eye and that evening darkness comes far too quickly. While more daylight would be a lovely thing, the early darkness has one big advantage: the stars. On a clear evening you can look up and see far into space. I’ve spent many winter evenings with my children, on our way home from activities, looking for Orion (and other constellations), following its path through the seasons.

Stars and space are two of the most popular science topics, whatever the age of the child. There’s something awe-inspiring and beautiful about looking into the night sky at the stars.

But it isn’t just children and young people who are fascinated by stars – astronomy is one of the few sciences where amateurs can make a significant contribution to our understanding of the subject.

… and there came from the East

At this time of year, the Christmas story can serve as a reminder that, throughout history, people have looked at the night sky, and wondered about what they have seen. The Babylonians had star catalogues as early as 1300 BC which contained information about constellations and patterns in the stars. It’s likely that the observation and naming of these constellations went back before that date.

The stars and constellations were important to those observing them. According to biblical tradition, after Jesus was born, magi (or wise men) from the east came to find Jesus saying that they had seen his star when it rose and followed it. The magi were people who studied the stars and saw significance in them.

Water discovered in a small, warm exoplanet’s atmosphere for first time

The planet is a ball of gas with surface temperatures of 600C, but future studies of alien atmospheres may reveal signs of life.

 

 

Astronomers have detected water vapour in the atmosphere of a planet that orbits a star far beyond our solar system.

Observations of the Neptune-sized planet, which lies 120 light years from Earth in the constellation of Cygnus, revealed that its atmosphere was mostly hydrogen with around 25% made up from water vapour.

Until now, researchers have been frustrated in their efforts to study the atmospheres of planets much smaller than Jupiter because their skies were thick with clouds. The problem was so persistent that astronomers had begun to think that all warm, small planets formed with substantial cloud cover.

But writing in the journal Nature, scientists in the US describe how they found a Neptune-sized planet with cloud-free skies, enabling them to make detailed measurements of a small planet’s atmosphere for the first time.

The planet, named HAT-P-11b, is about four times the diameter of Earth. It orbits so close to its star that surface temperatures reach more than 600C and a year passes in five Earth days. Like our own Neptune, the planet lacks a rocky surface – it’s a ball of gas – and is thought to be lifeless.

Scientists from the University of Maryland used Hubble’s wide field camera to analyse light from HAT-P-11b’s host star through the planet’s atmosphere. They found that light with a wavelength of 1.4 micrometres was absorbed, matching the absorption spectrum of water molecules.

“Although this planet is not classically habitable, it reveals to us that when we find Earth 2.0, we will be able to use this technique, transmission spectroscopy, to understand its atmosphere and determine the quality of life available on its shores,” said Jonathan Fraine, a graduate student and first author on the study.

What are asteroids?

Unless they’re ‘trojans,’ most of these space rocks fly in a belt between the orbits of Mars and Jupiter.

 
The solar system contains millions of asteroids. They may be round or oblong. Some have even stranger shapes, as though molded in play dough and left in space to harden. All are made from the same stuff as the planets. However, unlike rocks on Earth, those that make up asteroids have not been shaped by erosion, heat or intense pressure.

All asteroids are fairly small. Their diameters tend to range from less than a kilometer (a little more than half a mile across) to nearly 1,000 kilometers (621 miles across). Together, all of the asteroids in our solar system have a combined mass that is less than that of Earth’s moon.

Some asteroids resemble small planets. More than 150 of them have their own moon. Some even have two. Still others orbit with a companion asteroid; these pairs race circles around each other as they orbit the sun.

The orbits of most fall in a swath of space between Mars and Jupiter. It’s known, naturally enough, as the asteroid belt. But that's still a lonely neighborhood: An individual asteroid is usually at least a kilometer (0.6 mile) away from its nearest neighbor.

Asteroids called trojans don't inhabit the belt. These rocks may follow a larger planet's orbit around the sun. Scientists have identified nearly 6,000 trojans that follow along in Jupiter's orbit. Earth has only one known trojan.

Astronomers Find Slow-Cooked Diamond the Size of Earth

About 900 light-years away, an ancient white dwarf star has cooled into a crystallized chunk of carbon — a diamond. But this isn’t just any old diamond hiding in space: It’s the size of Earth, and it’s 11 billion years old.

The diamond-star, described in a study published in The Astrophysical Journal, is among the coldest white dwarfs astronomers have found. In fact, it’s so cool and dim that it can’t even be seen — its feeble light isn’t nearly powerful enough to pierce the darkness of the cosmos, even from relatively nearby.

Instead, teams inferred the presence of the crystallized dwarf based on the way its gravity perturbs the normally steady radio pulses coming from a spinning companion star.

Yep, the system gets even cooler. The dwarf is orbiting a pulsar — a rapidly rotating neutron star — known by the charismatic moniker PSR J2222-0137. The system is similar to another that was described in 2011, with a crystallized white dwarf orbiting a pulsar — but this new diamond is bigger (there’s also a planet hypothesized to be somewhat diamond-like).

If you were to look in the sky in the direction of the constellation Aquarius, you’d be looking in roughly the right direction to see the system, which is actually a pair of dead stars: The spinning neutron star is the extremely dense remnant of a formerly huge star that ended its life in a supernova. A white dwarf is all that remains of a formerly Sun-like star, contracted into a clump the size of Earth. Left on their own, dwarfs will slowly cool and fade to black over billions of years (but sometimes, with the help of a stellar companion, they can detonate and create dazzling supernovas the outshine entire galaxies).

Monster collision in space

Four clusters of galaxies are smashing into each other.

BOSTON — A galactic pileup is underway 5 billion light-years from Earth. The colossal collision is spewing charged particles. And this fountain is huge. It’s jetting particles at nearly the speed of light some 2.5 million light-years into intergalactic space. One might think of the event as building a powerful particle accelerator — one up to a million times as strong as Earth’s mightiest (the Large Hadron Collider).

Astronomers reported the intergalactic fireworks at the American Astronomical Society meeting, here, on June 3. They observed the smashup in new images compiled by two telescopes. NASA’s Chandra X-ray Observatory, a satellite system, eyed the event from an altitude of 139,000 kilometers (86,500 miles) above Earth’s surface. A radio telescope, the Very Large Array, homed in on the collision from the ground. Its 27 antennas are splayed out across the New Mexico desert.

And the source of all the commotion? Four clusters of galaxies are crashing into each other. Together, they involve a mass equal to 3 million billion suns.
Galaxy clusters are the largest structures in the universe that are linked by gravity, notes Reinout van Weeren. He works at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. Large clusters can house thousands of galaxies. Astronomers think these built up over billions of years as smaller clusters merged.

Nasa Kepler telescope discovers planet believed to be most Earth-like yet found

Kepler-186f is 10% bigger and occupies its star's 'habitable zone' where temperatures would allow liquid surface water.

A newly discovered planet may be the most Earth-like yet found in another solar system, scientists believe.

Kepler-186f is almost the same size as the Earth and occupies its star's "habitable zone" where temperatures are mild enough to allow liquid surface water.

If the planet has lakes or oceans, it would increase the chances of life evolving there.

But anything living on the world may have to withstand extra large doses of radiation from its active sun, Kepler-186.

The find is described in the journal Science as "a landmark on the road to discovering habitable planets".

Smaller and cooler than our sun, Kepler-186 is classified as an M-dwarf star, is 795 light years away and is orbited by five known planets.

Kepler-186f, the latest to be discovered, is the outermost plant in the system.

The planet was found by astronomers scouring the Milky Way galaxy for potentially habitable worlds