Universe Today

September 19, 2012April 26, 2016 by Fraser Cain

Using Gravity to Peer into the Most Violent Places in the Universe: Colliding Black Holes

Simulation of colliding black holes

Nothing matches the destructive power of a black hole; a singularity of dense matter with a gravitational pull so strong that nothing, not even light can escape. What goes in, doesn’t come back out. And so you can imagine how difficult it would be to probe the region inside a black hole’s event horizon. And yet, there’s a catastrophic event that should give scientists a momentary glance into the maelstrom, to partly understand what’s going on “in there.” That event would be the collision between two black holes.

As you probably know, there’s a supermassive black hole lurking at the heart of every galaxy. As these galaxies merge, these black holes encounter one another too. Sometimes a black hole is violently kicked into deep space, and other times they merge together into an even more super-supermassive black hole. The collision happens out of sight, beneath the shared event horizon. So, there’s no way to see what’s going on … and live to tell about it.

By looking at the gravity, however, astronomers might be able to peer right into the collision zone. One of the predictions made by Albert Einstein, as part of his famous General Theory of Relativity, is that dramatic gravitational events in the Universe, like the formation or collision of black holes should be detectable by the gravitational waves they generate. As these waves wash over us, the ripples in spacetime should be detectable by extremely sensitive instruments or spacecraft flying in formation.

A team of researchers from Cardiff University, Ioannis Kamaretsos, Mark Hannam and B. Sathyaprakash, have used a powerful supercomputer to simulate what kinds of gravitational waves might be generated by merging black holes. Two black holes orbiting one another should be emitting gravitational waves and gradually losing energy. This causes them to spiral inward, collide, and create a black hole which is highly deformed.

According to their simulation, the gravitational waves from this deformed black hole will give off a distinctive “tone”, like a ringing bell. In fact, by measuring only this tone, astronomers will be able to deduce both the mass of the black hole and the speed of its spin. Furthermore, the distortion of the gravitational waves should allow researchers to “see” what’s going on within the black hole’s event horizon; to understand what happened to the merging monsters after they disappeared beneath the shared event horizon.

“By comparing the strengths of the different tones, it is possible not only to learn about the final black hole, but also the properties of the original two black holes that took part in the collision,” Ioannis Kamaretsos said in a news release.

Of course, it’s important to note that gravitational waves themselves are still purely theoretical. Even though there are multiple ground-based detectors already built, and even more sensitive space-based detectors on the way, there hasn’t been a direct detection of a gravitational wave yet, only indirect detections. However, I wouldn’t bet against Einstein. He’s had a pretty good track record.

Original Source: Cardiff News Release

September 18, 2012January 4, 2016 by Nancy Atkinson

Timelapse: Space Shuttle Endeavour Mated to 747

Watch carefully, as this will be the last time ever this event will ever happen. At the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida, space shuttle Endeavour was mounted atop NASA’s Shuttle Carrier Aircraft, or SCA, in preparation for its ferry flight to California. The SCA, a modified 747 jetliner, will fly Endeavour to Los Angeles later this week, where it will be placed on public display at the California Science Center. This is the final ferry flight scheduled in the Space Shuttle Program era.

September 18, 2012December 23, 2015 by Fraser Cain

Planets Found in a Cluster of Buzzing Stars

Artist's illustration of a planet within a cluster. Image credit: NASA/JPL-Caltech

Artist’s illustration of a planet within a cluster. Image credit: NASA/JPL-Caltech

There’s a classic science fiction story called Nightfall, written by the late-great Isaac Asimov. It’s the tale of a world with six suns that fill the sky with such brightness that the inhabitants have no concept of night. And then one day, a once-in-a-thousand-years alignment causes all the stars to set at once; and everyone goes crazy!

In another case of science following science fiction, NASA-funded astronomers have discovered planets orbiting within a dense cluster of stars called the Beehive Cluster; a collection of 1,000 stars collected around a common center of gravity – Nightfall worlds?!

Well, not so fast. These worlds are “hot Jupiters;” massive, boiling hot planets that orbit their parent star closer than Mercury in our own Solar System. The two new planets have been designated Pr0201b and Pr0211b after “Praesepe”, another name for the Beehive Cluster. Although they aren’t habitable, the view from those planets in a dense cluster of stars would be awe inspiring, with hundreds of stars within a radius of 12 light-years.

Astronomers had long predicted that planets should be common in star clusters. Consider that our own Solar System probably formed within a star forming complex like the Orion Nebula. Then the individual stars drifted away from each other over time, taking their planets with them. The evolution of the Beehive cluster was different, though, with the mutual gravity of the 1,000+ stars holding themselves together over hundreds of millions of years.

“We are detecting more and more planets that can thrive in diverse and extreme environments like these nearby clusters,” said Mario R. Perez, the NASA astrophysics program scientist in the Origins of Solar Systems Program. “Our galaxy contains more than 1,000 of these open clusters, which potentially can present the physical conditions for harboring many more of these giant planets.”

Until now, only two planets had been uncovered around massive stars in star clusters, but none around sun-like stars within these clusters. So the possibility of life was out of the question. These super-jupiters aren’t habitable either, but it’s possible that smaller planets will turn up in time as well.

Beehive Cluster. Image credit: Tom Bash and John Fox/Adam Block/NOAO/AURA/NSF

The planets were discovered by using the 1.5-meter Tillinghast telescope at the Smithsonian Astrophysical Observatory’s Fred Lawrence Whipple Observatory near Amado, Arizona to measure the slight gravitational wobble the orbiting planets induce upon their host stars.

This discovery might help astronomers with another mystery that has been puzzling them for a few years: how can hot Jupiters form? How can a massive planet form so close to their parent star? Instead of forming close, it’s possible that the constant gravitational interactions among stars in young clusters push planets back and forth. Some are spun out into space as rogue planets, while others spiral inward and settle into these tight orbits.

Could there be life on Earth-sized worlds within these clusters? Are there civilizations out there who have never known the concept of night?

Probably not.

According to other researchers who released their findings just a week before the Tillinghast study, planets within star clusters like the Beehive probably aren’t habitable. In a paper titled, Can habitable planets form in clustered environments?, a team of European astronomers considered the environmental effects of star clusters on the formation and evolution of planetary systems. According to their simulations, there are just too many dynamic gravitational encounters with other stars in the cluster for any planet to remain long in the habitable zone.

Source: NASA News Release

September 18, 2012December 23, 2015 by Jason Major

35 Years Ago: Our First Family Portrait of the Earth and Moon

A crescent Earth and Moon as seen by Voyager 1 on September 18, 1977 (NASA)

35 years ago today, September 18, 1977, NASA’s Voyager 1 spacecraft turned its camera homeward just about two weeks after its launch, capturing the image above from a distance of 7.25 million miles (11.66 million km). It was the first time an image of its kind had ever been taken, showing the entire Earth and Moon together in a single frame, crescent-lit partners in space.

The view of Earth shows eastern Asia, the western Pacific Ocean and part of the Arctic. Voyager 1 was actually positioned directly above Mt. Everest when the images were taken (the final color image was made from three separate images taken through color filters.)

The Moon was brightened in the original NASA images by a factor of three, simply because Earth is so much brighter that it would have been overexposed in the images were they set to expose for the Moon. (Also I extended the sides of the image a bit above to fit better within a square format.)

Read the latest on Voyager 1: Winds of Change at the Edge of the Solar System

Previous images may have shown the Earth and Moon together, but they were taken from orbit around one or the other and as a result didn’t have both worlds fully — and in color! — within a single frame like this one does. In fact, it was only 11 years earlier that the very first image of Earth from the Moon was taken, acquired by NASA’s Lunar Orbiter I spacecraft on August 23, 1966.

It’s amazing to think what was happening in the world when Voyager took that image:
• World population was 4.23 billion (currently estimated to be 7.04 billion)
• The Space Shuttle Enterprise made its first test flight from a 747
• Star Wars, Close Encounters of the Third Kind and Saturday Night Fever were out in U.S. theaters
• Charlie Chaplin and Elvis Presley died
• U.S. federal debt was “only” $706 billion (now over $16 trillion!)
• And, of course, both Voyagers launched on their Grand Tour of the Solar System, ultimately becoming the most distant manmade objects in existence
(See more world stats and events here.)

Image: NASA/JPL

“Once a photograph of the Earth, taken from outside, is available – once the sheer isolation of the Earth becomes known – a new idea as powerful as any in history will be let loose.”
– Sir Fred Hoyle

September 18, 2012December 23, 2015 by Jason Major

NASA Probes Play the Music of Earth’s Magnetosphere

Launched on August 30, 2012, NASA’s twin Radiation Belt Storm Probe (RBSP) satellites have captured recordings of audible-range radio waves emitted by Earth’s magnetosphere. The stream of chirps and whistles heard in the video above consist of 5 separate occurrences captured on September 5 by RBSP’s Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrument.

The events are presented as a single continuous recording, assembled by the (EMFISIS) team at the University of Iowa and NASA’s Goddard Space Flight Center.

Called a “chorus”, this phenomenon has been known for quite some time.

“People have known about chorus for decades,” says EMFISIS principal investigator Craig Kletzing of the University of Iowa. “Radio receivers are used to pick it up, and it sounds a lot like birds chirping. It was often more easily picked up in the mornings, which along with the chirping sound is why it’s sometimes referred to as ‘dawn chorus.’”

The radio waves, which are at frequencies that are audible to the human ear, are emitted by energetic particles within Earth’s magnetosphere, which in turn affects (and is affected by) the radiation belts.

The RBSP mission placed a pair of identical satellites into eccentric orbits that will take them from as low as 375 miles (603 km) to as far out as 20,000 miles (32,186 km). During their orbits the satellites will pass through both the stable inner and more variable outer Van Allen belts, one trailing the other. Along the way they’ll investigate the many particles that make up the belts and identify what sort of activity occurs in isolated locations — as well as across larger areas.

Read: New Satellites Will Tighten Knowledge of Earth’s Radiation Belts

Audio Credit: University of Iowa. Visualisation Credit: NASA/Goddard Space Flight Center. (H/T to Peter Sinclair at climatecrocks.com.)

September 17, 2012December 23, 2015 by Jason Major

Manhattan-Sized Ice Island Heads Out to Sea

An “ice island” that calved from the Petermann Glacier in July is seen by NASA satellite (MODIS/Terra)

Remember that enormous slab of ice that broke off Greenland’s Petermann Glacier back in July? It’s now on its way out to sea, a little bit smaller than it was a couple of months ago — but not much. At around 10 miles long and 4.6 miles across (16.25 x 7.5 km) this ice island is actually a bit shorter than Manhattan, but is fully twice as wide.

The image above was acquired on September 14 by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite.

Although the calving of this particular ice island isn’t thought to be a direct result of increasing global temperatures, climate change is thought to be a major factor in this year’s drop in Arctic sea ice extent, which is now below 4.00 million square kilometers (1.54 million square miles). Compared to September conditions in the 1980s and 1990s, this represents a 45% reduction in the area of the Arctic covered by sea ice.

Arctic sea ice extent data for June-July 2012 (NSIDC)

This year sea ice in the Arctic Ocean dropped below the previous all-time record, set in 2007. 2012 also marks the first time that there has been less than 4 million square kilometers (1.54 million square miles) of sea ice since satellite observations began in 1979.

The animation below, released today by the NOAA, shows the 2012 time-series of ice extent using data from the DMSP SSMI/S satellite sensor:

First Images in a New Hunt for Dark Energy

Zoomed-in image from the Dark Energy Camera of the barred spiral galaxy NGC 1365, about 60 million light-years from Earth. (Dark Energy Survey Collaboration)

The ongoing search for dark energy now has a new set of eyes: the Dark Energy Camera, mounted on the 4-meter Victor M. Blanco telescope at the National Science Foundation’s Cerro Tololo Inter-American Observatory in Chile. The culmination of eight years of planning and engineering, the phone-booth-sized 570-megapixel Dark Energy Camera has now gathered its very first images, capturing light from cosmic structures tens of millions of light-years away.

Eventually the program’s survey will help astronomers uncover the secrets of dark energy — the enigmatic force suspected to be behind the ongoing and curiously accelerating expansion of the Universe.

Zoomed-in image from the Dark Energy Camera of the Fornax cluster

“The Dark Energy Survey will help us understand why the expansion of the universe is accelerating, rather than slowing due to gravity,” said Brenna Flaugher, project manager and scientist at Fermilab.

The most powerful instrument of its kind, the Dark Energy Camera will be used to create highly-detailed color images of a full 1/8th of the night sky — about 5,000 square degrees — surveying thousands of supernovae, galactic clusters and literally hundreds of millions of galaxies, peering as far away as 8 billion light-years.

The survey will attempt to measure the effects of dark energy on large-scale cosmic structures, as well as identify its gravitational lensing effects on light from distant galaxies. The images seen here, acquired on September 12, 2012, are just the beginning… the Dark Energy Survey is expected to begin actual scientific investigations this December.

Full Dark Energy Camera composite image of the Small Magellanic Cloud

“The achievement of first light through the Dark Energy Camera begins a significant new era in our exploration of the cosmic frontier,” said James Siegrist, associate director of science for high energy physics with the U.S. Department of Energy. “The results of this survey will bring us closer to understanding the mystery of dark energy, and what it means for the universe.”

Read more on the Symmetry Magazine article here, and you can also follow the Dark Energy Survey on Facebook here. (The Fermilab press release can be found here.)

Images: Dark Energy Survey Collaboration. Inset image: the 4-meter Blanco Telescope dome at CTIO (NOAO)

The Dark Energy Survey is supported by funding from the U.S. Department of Energy; the National Science Foundation; funding agencies in the United Kingdom, Spain, Brazil, Germany and Switzerland; and the participating DES institutions.

September 17, 2012December 23, 2015 by Jason Major

Curiosity Captures a Martian Eclipse

Yes, Mars gets eclipses too! This brief animation, made from ten raw subframe images acquired with Curiosity’s Mastcam on September 13 — the 37th Sol of the mission — show the silhouette of Mars’ moon Phobos as it slipped in front of the Sun’s limb.

The entire animation spans a real time of about 2 minutes.

As a moon Phobos really is an oddity. In addition to its small size – only 8 miles (13 km) across at its widest – and irregular shape, it also orbits its parent planet at a very low altitude, only 5,840 miles (9,400 km) and thus needs to travel at a relatively high velocity in order to even stay in orbit. Phobos actually orbits Mars over three times faster than Mars rotates, appearing to rise in Mars’ western sky. And its orbit is so low that it can’t even be seen from the polar regions!

Since Phobos, and its even more petite sibling Deimos, are so small, the Mars rovers won’t ever see a total solar eclipse. In fact these events are often referred to as transits rather than actual eclipses.

This isn’t the first time an eclipse was captured by a Mars Exploration Rover; Opportunity witnessed a similar partial eclipse of the Sun by Phobos in December 2010, and Spirit caught a lunar (or “Phobal?”) eclipse on camera back in 2005, when the moon passed into the shadow of Mars.

Curiosity’s find was no accident, either, as mission engineers had the Mastcam already positioned to capture the event. Preparation really pays off!

See the latest images and news from the MSL mission here.

Images: NASA/JPL-Caltech/Malin Space Science Systems. Animation by Jason Major. Inset image: Phobos as seen by Mars Express ESA/DLR/FU Berlin (G. Neukum)

UPDATE 9/19/12: See a close-up animation of the eclipse event here.

September 17, 2012 by Fraser Cain

Virtual Star Party, Sep. 16, 2012: The Dark Time Edition

No pesky Moon to drown out our view of the night sky this week, so it’s time to delve deep into the faint dark sky objects.

We were down to a single telescope this week for our Virtual Star Party… but what a telescope! Gary Gonella took us through a massive series of objects, rapid fire, with Nicole, Scott and Thad bringing the science.

Host: Fraser Cain

Telescopes: Gary Gonella, Roy Salisbury

Commentators: Scott Lewis, Dr. Nicole Gugliucci, Dr. Thad Szabo

We have a Virtual Star Party on Google+ every Sunday night when it gets dark on the West Coast of North America.

Click here to put next week’s event right into your calendar.

If you’re an astronomer with the ability to stream images from your telescope into your computer, we’d love your help. Just email Fraser Cain at [email protected] and I’ll help you connect up your view into a Virtual Star Party.

September 17, 2012December 23, 2015 by Nancy Atkinson

Astrophoto: Stunning Starscape by Sean Parker

A great shot of the beautiful night-time sky by astrophotographer Sean Parker! Sean used a Canon 5DMKII, Nikkor 14-24MM F/2.8 at 20 seconds and ISO 1000, and processed the image with Adobe Lightroom. See more of Sean’s work at his Flickr page, or his G+ page.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.