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Perception of the surreal by Younes Ahlafi

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ikenbot:

Corpse Stars Could Nurture Life on Alien Planets

White dwarfs may be dying, but their light could be just right to sustain life as we know it. That could make habitable planets even more common than we think.

Many planet-hunting missions have focused on finding rocky exoplanets around sun-like stars, based on the notion that an exact Earth twin would be a prime breeding ground for alien life.

White dwarfs, by contrast, would seem unlikely hosts. These smouldering cores form when stars around the same mass as our sun reach the end of their lives. First the stars balloon to red giants, then they shed their outer gas layers and leave behind dim, ultradense orbs not much larger than Earth itself.

Still, previous work suggested that the stellar corpses could maintain habitable zones, regions where liquid water can exist on a planet’s surface, for more than 8 billion years. As our own solar system is 4.5 billion years old, a habitable world around a white dwarf should have plenty of time to give rise to some form of life.

Now a new study shows that an Earth-like planet in a white dwarf’s habitable zone would get light at the right wavelengths to sustain photosynthesis. Crucially, such a world would not get too much damaging ultraviolet radiation, which can stop life in its tracks.

Luca Fossati at the Open University in the UK and his colleagues started by assuming that this hypothetical planet has an atmosphere similar to Earth’s.

By simulating the conditions created by a white dwarf, the team calculated the amount of starlight that would reach the planet’s surface. They then compared the results with the wavelengths of light DNA absorbs, particularly UV waves known to damage DNA.

The researchers found that the planet would get just 1.65 times as much UV light as Earth does (arxiv.org/abs/1207.6210). “The dose is remarkably benign from an astrobiological perspective,” says Fossati.

For the optical wavelengths that play roles in photosynthesis, the team found conditions almost identical to those on Earth.

Planets surrounding red dwarf stars have also been proposed as alternative sites for life, says Fossati, in part because these small, cool stars are the most common in our galaxy. But they can experience intense stellar activity, including flares of radiation bigger than the ones that affect Earth. White dwarfs are less temperamental, and would provide life with a more stable home, says Fossati.

“The team’s evaluation of habitable planets at white dwarfs is an excellent way to smash preconceptions about these systems,” says Jay Farihi at the University of Leicester in the UK.

Full Article

mayshi:

Another shot of my studio. Still need to cover up majority of the walls, needs more space. :)

ikenbot:

Ritchey-Chreitien Telescope and the Milky Way

Milky Way and meteor streak above the dome of the 32” Ritchey-Chreitien telescope at Appalachian State University’s Dark Sky Observatory.

designcritter:

To go where no one has gone before.
“As long as there are history books, Neil Armstrong will be included in them, remembered for taking humankind’s first small step on a world beyond our own.” - Charles Bolden

contemplatingmadness:

These mirrors will allow us to observe the birth of the Universe. Yes, really.
In 2018, the James Webb Space Telescope will become one of the greatest tools in humanity’s quest to understand the cosmos. Now, after eight years, the technology comprising the heart and soul of the telescope — an ultra-sophisticated beryllium mirror system — is complete.
Up top, 11 of JWST’s 18 gigantic mirror segments, engineered and assembled by Ball Aerospace in Boulder, Colorado, are shown packed up and ready to ship to NASA. Here’s why that is very, very exciting news.
Yes, NASA just landed an absurdly awesome rover on the surface of Mars; and yes, the Agency did just announce plans for yet another mission to the Red Planet — but the completion of JWST’s primary mirror system represents a major milestone for a much bigger (and much more expensive) astronomical endeavor.
It is estimated that JWST will wind up costing roughly 9 billion dollars by the time NASA’s ready to hoist it into space. That’s over three times the estimated cost of the Curiosity project; but with that price tag comes formidable scientific potential. Not to detract from NASA’s accomplishments on Mars in any way, but JWST is designed to tell us about the earliest days of the Universe. When you’re dealing with cosmological questions on a scale as big as, well, the cosmos, you’re bound to come up with some monumental discoveries.
How monumental are we talking? Look at it this way: in many ways, JWST is designed to help answer questions about the Universe that we haven’t even thought of yet — something its predecessor, the Hubble Space Telescope, has been remarkably successful at. Astronomers and astrophysicists are confident that the vastly superior capabilities of JWST will translate to discoveries of a similar caliber.
That confidence is captured perfectly in this description of JWST by astrophysicist Michael Shara, curator in the Department of Astrophysics at the American Museum of Natural History (click here for our full interview with Shara):

[The James Webb Space Telescope] has, in many ways, 100 times the capabilities that the Hubble Space Telescope does. We’re actually going to be able to see the first stars forming, the first galaxies forming after the Big Bang. We’re also going to be able to — we think — directly image planets orbiting other stars.
There isn’t a field in all of astrophysics that will not benefit tremendously. Just as Hubble was… not just a leap, but an enormous leap forward for all of astrophysics, including the discovery of Dark Energy (70% of… the energy of the Universe was unknown before Hubble), I find it almost impossible to believe that we won’t make the same kinds of discoveries with the James Webb Telescope.
Once [we] started seeing things with Hubble that [we’d] never seen before, [we] pushed it harder and harder to do new things. The same will happen with the James Webb Space Telescope. We will discover new things that we have no way of knowing about today, no way of guessing [because] our intuition isn’t able to take us there. And those will be the great discoveries that actually show up in the coming 20 years, in the coming 30 years. It is really, in many ways, the golden age of astronomy — it’s the very best time ever to be an astronomer.

To the uninformed observer, this view of JWST’s 18 mirror segments, all packed up and ready for transport, is little more than some shiny eye-candy. But to those familiar with the telescope and its awesome scientific potential, it represents the completion of one of the most challenging stages on the path to JWST’s full realization.

ikenbot:

Giant Dying Star Caught Devouring Alien Planet

Image: This artist’s impression shows a red giant engulfing a Jupiter-like planet as it expands. Credit: NASA

A swollen star near the end if its life has been caught devouring one of its own planets — a scenario that could one day be replayed on Earth when our own sun dies in billions of years, scientists say.

Astronomers discovered the cosmic crime scene while studying an ancient star that has expanded in its old age to became a so-called “red giant.” The star, called BD+48 740, is older than our sun and much bigger. Its radius is 11 times larger than that of our sun.

As the star swelled into a red giant, it likely absorbed its innermost planet, researchers said.

“A similar fate may await the inner planets in our solar system, when the sun becomes a red giant and expands all the way out to Earth’s orbit some five billion years from now,” study team member Alex Wolszczan, an astronomer at Pennsylvania State University, said in a statement. The Earth orbits the sun at a distance of about 93 million miles (150 million kilometers).

Two key pieces of evidence identified the star as a planet-killer, researchers said.

First, the astronomers found abnormally high amounts of lithium, a rare element in the universe, inside the star. That fact alone hinted that a missing planet may be involved.

“In the case of BD+48 740, it is probable that the lithium production was triggered by a mass the size of a planet that spiraled into the star and heated it up while the star was digesting it,” said Wolszczan, who led the team that discovered the first planets beyond our solar system, back in 1992.

Then there was the strange orbit of a giant planet discovered around the star. The huge planet is about 1.6 times as massive as Jupiter and circles the star in an extremely elliptical orbit.

“We discovered that this planet revolves around the star in an orbit that is only slightly wider than that of Mars at its narrowest point, but is much more extended at its farthest point,” said study team member Andrzej Niedzielski of Nicolaus Copernicus University in Torun, Poland. “Such orbits are uncommon in planetary systems around evolved stars and, in fact, the BD+48 740 planet’s orbit is the most elliptical one detected so far.”

Full Article

opticoverload:

2012 Perseids meteor shower over the snowy range in Wyoming