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Our galaxy is positively stuffed with alien worlds.

That exoplanets swarm the Milky Way, and that a good fraction of them are small, rocky, and temperate like the planet we live on, means the search for life beyond Earth is moving past the question of whether these worlds are common and on to the more profound question of whether those faraway worlds also host life.

“We’re no longer wondering if rocky planets are in the habitable zones of stars,” the University of Arizona’s Olivier Guyon said during last week’s Breakthrough Discuss conference, hosted by the Breakthrough Initiatives. “As far as we can tell, they’re everywhere. We’re transitioning into life-finding. We have a lot of work ahead of us.”

http://news.nationalgeographic.com/2017/04/new-planets-life-close-earth-space-science/

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Astronomers scramble to probe 'alien megastructure' star


KIC 8462852, also known as Tabby's Star, has been monitored for several years after it was noticed that its brightness changed significantly and at irregular intervals.

A range of theories have been put forward for this strange behaviour, including one hypothesis which suggests an alien megastructure may have been built around the star to harvest its energy.

Although the star was first discovered in the 1890s, it was not until observations between 2009 and 2013 when scientists first noticed something particularly odd about it.

It was subsequently named after Louisiana-based astronomer Tabetha Boyajian, who wrote a paper about its strange behaviour.

Professor Boyajian noticed that at one point Tabby's Star's brightness had dropped by 22%, which can not be explained by any properly understood phenomenon.

Last month scientists noticed what appeared to be another slight dimming of the star - but that accelerated significantly on Friday, causing a scramble for additional observations.

Jason Wright, associate professor of astronomy and astrophysics at Penn State University, told a web chat: "One of the difficulties here is that most telescopes are scheduled weeks, months in advance.

"We can't just jump on a telescope and take a spectrum typically. So we need to have a network of people around the world."

Tabby's Star is in the constellation Cygnus and is approximately 1,275 light years from Earth.

Scientists hope they might be able to work out what is causing the star to dim by analysing its full spectrum of light. But to do this, they need to know when that dimming is going to occur.

Astronomers do not believe it is being caused by a planet passing in front the star as this would not cause such a significant change in brightness, and it would be more predictable.

A number of other theories have been put forward. One suggests there may be a large cloud of dust and debris around the star.

Another suggestion is that it is recovering having been hit by a planet and a third theory suggests a swarm of comets may be responsible.

The most unusual suggestion - but one which scientists can not yet dismiss - is that an alien megastructure has been built around the star to harvest its energy.

The concept, which sounds like it comes straight out of science fiction, is actually referred to as as Dyson Sphere.

It is named after British-born scientist Freeman Dyson who, in the 1960s, hypothesised that advance civilisations would seek to power their worlds in this way.

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Jupiter: Juno Perijove 06

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NASA's Juno Spacecraft to Fly Over Jupiter's Great Red Spot July 10


Just days after celebrating its first anniversary in Jupiter orbit, NASA's Juno spacecraft will on July 10 fly directly over Jupiter's Great Red Spot, the gas giant's iconic, 10,000-mile-wide (16,000-kilometer-wide) storm. This will be humanity's first up-close and personal view of the gigantic feature -- a storm monitored since 1830 and possibly existing for more than 350 years.

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The great red spot of Jupiter as never seen before – in pictures

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Future astronauts could be drinking Moon water

The Moon's surprisingly extensive sub-surface water reserves could potentially be extracted and used "for future exploration".

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Saturn probe's fiery demise animated by scientists

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'Zombie' star won't die, even after exploding

It's the star that won't die, even though it has exploded and appeared to go down in a blaze of glory multiple times. This superlong supernova may be the first of its kind.

When they first observed supernova iPTF14hls in September 2014, astronomers at Las Cumbres Observatory in California thought it was perfectly normal. They analyzed the light of the explosion to study the material ejected and its speed.

But Zheng Chuen Wong, an intern at the observatory from the University of California, Santa Barbara, noticed something strange about the supernova and showed it to Iair Arcavi, a NASA Einstein postdoctoral fellow at the university.

A supernova, the massive explosion of a star, usually signals the end. Typically, a supernova remains bright for 100 days before fading. But this one fluctuated by brightening and dimming over the course of 600 days, according to a study released in the journal Nature on Wednesday.

The brightness of a supernova provides a luminosity equaling that of about 100 million suns.

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Oumuamua: Lost interstellar asteroid enters solar system


The dark red rock, named Oumuamua, is the first space rock from outside the solar system ever observed by astronomers.

A lost interstellar asteroid has entered the solar system after wandering between the stars for hundreds of millions of years, scientists believe.

The dark red object named Oumuamua, is about 400 metres (1,312 ft) long, scientists reported in the journal Nature.

It is the first space rock from outside the solar system ever observed by astronomers.

A telescope in Hawaii designed to spot Near-Earth Objects (NEOs) spotted the asteroid on 19 October as a faint point of light moving in the sky.

After further observations and orbital calculations, there was no doubt the object originated from outside the solar system.

Moving at 95,000 kilometres per hour (59,030 mph), Oumuamua was at first thought to have travelled from the bright star Vega, 25 light years away in the northern constellation of Lyra.

But Vega was nowhere near its current position 300,000 years ago, when its journey would have started.

That has led scientists to speculate that the asteroid is an interstellar wanderer that happens to have stumbled across our solar system.

"Oumuamua may well have been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with the solar system," Dr Karen Meech, from the Institute for Astronomy in Hawaii, said.

"This unusually large variation in brightness means that the object is highly elongated," she added.

"We also found that it has a dark red colour, similar to objects in the outer solar system, and confirmed that it is completely inert, without the faintest hint of dust around it."

The rock's properties suggest it could have a high metal content and lacks significant amounts of water or ice, and its surface has become dark and red by the impact of cosmic rays over millions of years.

Astronomers estimate that interstellar asteroids pass through the inner solar system about once a year, but they are difficult to see because they are so faint.

Oumuamua was discovered by the 1.8 metre Pan-STARR telescope in Hawaii, which is part of a system set up to track potentially threatening NEOs.

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Scientists accidentally engineer plastic-eating enzyme

British scientists have engineered an enzyme which can digest polyethylene terephthalate (PET), the plastic used in single-use plastic bottles and other common packaging.

Tests showed that the lab-made mutant enzyme had a supercharged ability to break down PET, one of the most popular forms of plastic used by the food and drinks industry.

Bottles made from PET are used to package 70% of soft drinks, fruit juices and mineral waters, according to the British Plastics Federation.

PET persists for hundreds of years in the environment before it degrades and the discovery may mean that significantly more plastic waste could be recycled.

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Japanese spacecraft reaches diamond-shaped asteroid after 3-year journey

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Best evidence yet for alien life on Saturn's moon found by scientists

Enceladus is only body besides Earth known to 'simultaneously satisfy all of the basic requirements for life as we know it', say scientists

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First confirmed image of the birth of a planet

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Ghost particle sent from deep in space could change our understanding of the universe

A single strange particle from deep space may shed light on some of the mysteries of the universe.

The tiny, ghost like subatomic particle was ejected from an incredibly energetic galaxy four billion light years away and could solve the century old mystery of where cosmic rays come from, as well as providing an entirely new way of looking at the cosmos.

The mysterious particle made its way to scientists from the most extreme environments in the universe, and will give them an unparalleled look at those intriguing regions.

The neutrino is the first of its kind detected and its likely origin was traced to a “blazar” four billion light years away. There, it was thrown out by a galaxy with a vast black hole at its centre, flung across the universe as the cosmic consumes matter.

Neutrinos could be doubly helpful because they have no mass and travel in an almost entirely straight line through the universe – which makes them very difficult to detect but very easy to track, as they travel billions of light years.