Sunday, March 11, 2018

Interstellar message of ‘Oumuamua

Mysterious traveller from afar highlights a seasonal greeting.

In October, a group of wise women and men spotted a mysterious light in the sky. There has been much excited chatter since about what it might mean. A space rock has come travelling. And as December draws to a close, the unusual visitor is heading away again, its brief message to Earth seemingly delivered. Our interstellar guest is from another star system entirely, one it was bundled out of perhaps even billions of years ago. Long-predicted, this is the first confirmed visit of an object from so far away. We are probably its first company in some time. And already it has seen enough.
A bright light shone around it. Long-term exposure to cosmic rays has created an insulating organic-rich layer on its surface (A. Fitzsimmons et al. Nature Astron.; 2017). This coating — more pink than silver — could have protected an ice-rich interior from being vaporized during its passage close to the Sun. And it could help to explain some of the initial confusion over the visitor’s true nature. Sky-watchers scanning for interstellar objects tend to be on the look-out for a comet. These are expected to produce a distinctive haze as their outer layers of ice sublimate, making them much easier to spot as they pass close to the Sun.

The absence of a tail saw the object reassigned instead as a rocky asteroid, which it could be. But its organic shield protects the unlikely possibility that it could be a comet after all — models suggest ice might be hidden underneath, undisturbed by the body’s flirtation with the Sun.

It could come from a planet a long way from here. If it is not a comet, a paper posted to the arXiv server this month speculates, it might be a fragment of a distant planet ripped apart by a process of gravitational vandalism known as tidal disruption (M. Ćuk preprint at; 2017).

Despite the best listening efforts of telescopes on Earth, the object has remained silent. And to the disappointment of alien-hunters across the planet, there is no sign of technology. (It was always a long shot, but the unusual cigar-shape boosted hopes that it was built and not formed.) Nonetheless, astronomers have called it ‘Oumuamua, a Hawaiian term for scout. In Nature this week, its discoverers (who spotted it using the Pan-STARRS telescope on Hawaii’s Maui island) say the object seems to be a “messenger sent from the distant past to reach out to us”.

‘Oumuamua might not be talking but it could still be listening. At this time of year, it’s traditional for many radio stations across the United States to play the 1949 Hawaiian tune ‘Mele Kalikimaka’, which offers a greeting of love, peace, joy and compassion. As ‘Oumuamua speeds away there are worse impressions for it to take from Earth — even if, like most souvenirs, the significance is lost on many of the planet’s locals.


Tuesday, January 24, 2017

Coastal survivors: SA's rare, twisted trees

Coastal survivors: SA's rare, twisted trees

Updated October 13, 2016 15:21:00 Hundreds of years old and with their gnarled limbs and otherworldly appearance, the grove of dingley dell gum trees in Port Macdonnell's Clarke Park is a spectacular sight. Scattered across a narrow coastal strip from the Glenelg River across South Australia's south-east, the rare subspecies of South Australian blue gum has survived by its sheer hardiness.

Photographing one of the world's tallest trees

Photographing one of the world's tallest trees

Posted January 24, 2017 13:58:03 It took 67 days, 12,000 images and a climb to stomach-churning heights, but photographer Steven Pearce finally got the image he was after of the world's tallest flowering plant, Tasmania's eucalyptus regnans. The Styx Valley, past the township of Maydena, about 100 kilometres north-east from Hobart, is often damp, cold and foggy.

Monday, January 16, 2017

10 Bizarre Recently Discovered Animal Species - Listverse

10 Bizarre Recently Discovered Animal Species - Listverse

Animals Modern human beings have lived on Earth for about 200,000 years. In that time, we've been almost everywhere-on land, in the sea, and on (and under) the water. You'd think we'd pretty much seen it all. However, that's not the case. Whether we're talking reptiles, dinosaurs, sharks, fish, flies, arthropods, or worms, nature is full of surprises.

10 Stunning Hidden Paradises From Around The World - Listverse

10 Stunning Hidden Paradises From Around The World - Listverse

Travel You've heard of the Grand Canyon, the Galapagos Islands, and Venezuela's Angel Falls; you've probably even heard of more obscure natural wonders, like the needle-like rock forests at Tsingy de Bemaraha. But no matter how much of the Earth we cover, there's always something breathtaking just around the bend.

Wednesday, December 21, 2016

10 Oldest Geological Features On Earth

10 Oldest Geological Features On Earth - Listverse

Our World The oldest parts of Earth testify to a living world that has been moving and taking shape for eons. Whenever another is discovered, they bring with them new surprises, often confirm theories, or confuse scientists completely.

10 Amazing Things We’ve Learned About The Solar System In 2016

10 Amazing Things We've Learned About The Solar System In 2016 - Listverse

Space There are nearly 30 man-made spaceships out in the solar system right now gathering information about our planet's neighborhood. Every year, evidence is gathered to bolster some theories while others fall by the wayside. Here are just some of the highlights of what we've discovered about the solar system in 2016.