Lightning Armageddon Over Hilo, Hawaii

This video is from the Canada-France-Hawaii Telescope on Mauna Kea facing Hilo, Hawaii. It shows last night's unusual thunderstorm over the east side of the island.

Published on Dec 30, 2013

The Search For Earth-Like Planets

The search for Earth-like planets is reaching a fever-pitch. Does the evidence so far help shed light on the ancient question: Is the galaxy filled with life, or is Earth just a beautiful, lonely aberration? If things dont work out on this planet Or if our itch to explore becomes unbearable at some point in the future Astronomers have recently found out what kind of galactic real estate might be available to us. Well have to develop advanced transport to land there, 20 light years away. The question right now: is it worth the trip?

If things don't work out on this planet...

Or if our itch to explore becomes unbearable at some point in the future... 

Astronomers have recently found out what kind of galactic real estate might be available to us.

We'll have to develop advanced transport to land there, 20 light years away.... But that's for later.

The question right now: is it worth the trip? The destination is a star that you can't see with your naked eye, in the southern constellation Libra, called Gliese 581. 

Identified over 40 years ago by the German astronomer Wilhelm Gliese, it's a red dwarf with 31% of the Sun's mass... and only 1.3% of its luminosity. 

Until recently, the so-called M Stars like Gliese 581 flew below the radar of planet hunters. 

They give off so little energy that a planet would have to orbit dangerously close just to get enough heat. 

Now, these unlikely realms are beginning to show some promise... as their dim light yields to precision technologies... 

...as well as supercomputers... honed in the battle to understand global changes on this planet... Earth. 

Will we now begin to detect signs of alien life? 

Or will these worlds, and the galaxy itself, turn out to be lifeless... and Earth, just a beautiful, lonely aberration?

To some, like astronomer and author Carl Sagan, the sheer number and diversity of stars makes it, as he said, "far more likely that the universe is brimming over with life."

This so-called "many worlds" view can be traced back to ancient observers... in China, India, Greece and Egypt. The Qur'an, the Talmud, and many Hindu texts all imagined a universe full of living beings. 

In the 16th Century, this view got a boost from astronomer and mathematician Nikolas Copernicus... who came to believe that Earth is not the center of the universe, but revolves around the Sun.

Seven decades after Copernicus, Galileo Galilei used his newly developed telescope to show that our Sun was just one among countless other stars in the universe. 

By the modern era, the "many worlds" view held sway in scientific circles. A variety of thinkers considered what and who inhabited worlds beyond our own. 

From Martians desperate to get off their planet... to alien invaders intent on launching pre-emptive strikes against ours... or simple life forms on an evolutionary track to complexity.

But other thinkers have been struck by a different view.

The Greek philosophers Aristotle and Ptolemy believed that humans and Earth are unique. 

With the spread of Christianity, this Ptolemaic system became widely accepted. 

The latest variation on this theme is what's called the "Rare Earth" hypothesis. It holds that Earth and sophisticated life were the result of fortuitous circumstances that may not be easy to find again in our galaxy. 

Does the current search for planets shed light on this debate... sending it in one direction or the other?

So far, our only good reference for recognizing an Earth-like planet is... Earth. 

It does have some fortuitous characteristics... it's dense, it's rocky -- with a complex make-up of minerals and organic compounds -- and it has lots and lots of water. 

It's also got a nearly circular orbit around the Sun, at a distance that allows liquid water to flow... not too close and not too far away, in the so-called "Habitable Zone." 

That's defined as the range of distance from a parent star that a planet would need to maintain surface temperatures between the freezing and boiling points of water. 

Of course, that depends on the size of the planet, the make-up of its atmosphere, and a host of other factors. 

And whether the parent star is large; medium like the Sun; or small. 

Some scientists also believe we live in a "Galactic Habitable Zone." We're close enough to the galactic center to be infused with heavy elements generated by countless stellar explosions over the eons...

But far enough away from deadly gamma radiation that roars out of the center. 

If there is a galactic habitable zone... it's thought to lie 26,000 light years from the center... about where we are... give or take about 6,000 light years.

NASA's Next Flagship Space Telescope

NASA's James Webb Space Telescope — the notoriously over-budget new space observatory slated to launch in 2018 — is on time and still within its new budget, the project's chief said Wednesday (Jan. 9).

“Our budget still stands and the schedule remains the same,” Eric Smith, the space telescope's program director, told astronomers here at a town hall meeting during the 221st meeting of the American Astronomical Society.

Smith also outlined the future of the James Webb Space Telescope program in 2013 and With an $8.8 billion dollar price tag, JWST is destined to be one of the largest and most expensive projects in NASA history. Set to replace the venerable Hubble Space Telescope once it is launched, JWST will take infrared images of distant galaxies, probing the cosmos for hints and signals left behind from the Big Bang.

Of the four science instruments responsible for investigating those mysteries aboard the spacecraft, two were delivered to NASA in 2012. The Mid-Infrared Instrument (MIRI) — the instrument responsible for taking “Hubble-like” images of distant galaxies, comets and other heavenly bodies — was sent last year by the European consortium that built it. [Photos: The James Webb Space Telescope]

The Canadian Space Agency has also delivered its instrument: the Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph (FGS/NIRISS) that will also take high-quality images of other bodies in space.

NASA is still awaiting two more contributions: the Near-Infrared Camera (NIRCam) from Lockheed Martin and the University of Arizona, and the Near-Infrared Spectrograph (NIRSpec) from the European Space Agency, which is still in its early testing phases. Both instruments measure light on the infrared spectrum. All of the science instruments are set to be integrated by the end of 2013, officials say.

The telescope's tennis court-size sunshield is in the early stages of testing as well. The sunshield itself is too large to launch in an unfurled state, creating a unique problem for JWST scientists to solve. Instead of launching the telescope with the sunshield in place, NASA is planning to unroll the shield once the craft is in orbit. At one-third of the way complete, NASA scientists are now starting to practice rolling and unrolling the shield to see how it might unfurl in space after launch.

Once all four instruments are finished, researchers will combine them to test JWST as one cohesive unit. While final testing on the ground should begin in 2015, simulation testing using Optimal Trajectories by Implicit Simulation — a space telescope tester that mimics the temperature and environment of a space telescope in Earth’s orbit — won’t start until 2017, a year before launch.

JWST is also going to investigate a few objects a little closer to home.

Mike Brown, an astronomer from Caltech, detailed a few of the more promising applications for JWST within the solar system. Planetary scientists have been interested in understanding what composes comets, protoplanets and other mysterious space objects. 

JWST’s sensitive instruments should be able to deliver some information as to what elements created rocky and icy objects in the outer solar system, Brown said at the town hall meeting.

NASA officials, meanwhile, are hopeful that the JWST's predecessor — the iconic Hubble Space Telescope — will still be functioning by the time the new observatory launches. This week, agency officials said the 23-year-old Hubble telescope could potentially last through 2018, allowing for some overlap with the JWST mission that would be a boon for astronomers.

Via: "Live Science"

Astronomers Discover The Largest Structure In The Universe

An international team of astronomers, led by academics from the University of Central Lancashire (UCLan), has found the largest known structure in the universe. 

The large quasar group (LQG) is so large that it would take a vehicle travelling at the speed of light some 4 billion years to cross it. 

The team publish their results in the journal Monthly Notices of the Royal Astronomical Society.

Quasars are the nuclei of galaxies from the early days of the universe that undergo brief periods of extremely high brightness that make them visible across huge distances. These periods are 'brief' in astrophysics terms but actually last 10-100 million years.

Since 1982 it has been known that quasars tend to group together in clumps or 'structures' of surprisingly large sizes, forming large quasar groups or LQGs.

The coloured background indicates the peaks and troughs in the occurrence of quasars at the distance of the LQG. Darker colours indicate more quasars, lighter colours indicate fewer quasars. The LQG is clearly seen as a long chain of peaks indicated by black circles. (The red crosses mark the positions of quasars in a different and smaller LQG). The horizontal and vertical axes represent right ascension and declination, the celestial equivalent of longitude and latitude. The map covers around 29.4 by 24 degrees on the sky, indicating the huge scale of the newly discovered structure. Credit: R. G. Clowes / UCLan

The team, led by Dr Roger Clowes from UCLan's Jeremiah Horrocks Institute, has identified the LQG which is so significant in size it also challenges the Cosmological Principle: the assumption that the universe, when viewed at a sufficiently large scale, looks the same no matter where you are observing it from.

The modern theory of cosmology is based on the work of Albert Einstein, and depends on the assumption of the Cosmological Principle. The Principle is assumed but has never been demonstrated observationally 'beyond reasonable doubt'.

To give some sense of scale, our galaxy, the Milky Way, is separated from its nearest neighbour, the Andromeda Galaxy, by about 0.75 Megaparsecs (Mpc) or 2.5 million light-years.

Whole clusters of galaxies can be 2-3 Mpc across but LQGs can be 200 Mpc or more across. Based on the Cosmological Principle and the modern theory of cosmology, calculations suggest that astrophysicists should not be able to find a structure larger than 370 Mpc.

Dr Clowes' newly discovered LQG however has a typical dimension of 500 Mpc. But because it is elongated, its longest dimension is 1200 Mpc (or 4 billion light years) - some 1600 times larger than the distance from the Milky Way to Andromeda.

Dr Clowes said:

"While it is difficult to fathom the scale of this LQG, we can say quite definitely it is the largest structure ever seen in the entire universe. This is hugely exciting – not least because it runs counter to our current understanding of the scale of the universe.

"Even travelling at the speed of light, it would take 4 billion years to cross. This is significant not just because of its size but also because it challenges the Cosmological Principle, which has been widely accepted since Einstein. Our team has been looking at similar cases which add further weight to this challenge and we will be continuing to investigate these fascinating phenomena."

Via: "The Royal Astronomical Society"

How A Giant Telescope Works

Post by "CavalierZee"



Watch our videos commercial free on the SpaceRip app, available in the Apple and Google Play stores.

From ESOcast, explore the state-of-the-art technology behind the Very Large telescope, which has provided astronomers with an unequalled view of the Universe. To obtain the sharpest images of the sky, the VLT has to cope with two major effects that distort the images of celestial objects. The first one is mirror deformations due to their large sizes. This problem is corrected using a computer-controlled support system — active optics — that ensures that the mirrors keep their desired shapes under all circumstances. The second effect is produced by Earth's atmosphere, which makes stars appear blurry, even with the largest telescopes. Adaptive optics is a real-time correction of the distortions produced by the atmosphere using computer-controlled mirrors that deform hundreds of times per second to counteract the atmospheric effects.

As one demonstration of its power the VLT's sensitive infrared cameras, helped by adaptive optics, have been able to peer through the massive dust clouds that block our view to Milky Way's core. The images, taken over many years, have allowed astronomers to actually watch stars orbiting around the monstrous black hole that lies in the center of our galaxy. It was even possible to detect energetic flares from gas clouds falling into the black hole.