Nancy Atkinson, Author at Universe Today

October 27, 2008December 24, 2015 by Nancy Atkinson

Spock’s Solar System Looks Like Ours

This artist's conception shows the closest known planetary system to our own, called Epsilon Eridani. Credit: NASA/JPL/Caltech

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Back in 2000, astronomers discovered a Jupiter-sized planet orbiting the nearby star Epsilon Eridani. Since that star system is listed in some Star Trek lore as the location of the fabled planet Vulcan, astronomers joked they had found Spock’s homeworld. But enticing new discoveries of the Epsilon Eridani system implies it could be a younger twin to our own solar system. It has two rocky asteroid belts and an outer icy ring, making it a triple-ring system. The inner asteroid belt looks strikingly similar to the one in our solar system, while the outer asteroid belt holds 20 times more material. All of this material implies that unseen planets lie hidden, shaping the rings. But if another civilization possibly could have developed in this region, let’s hope they are more like Spock than Kirk’s evil twin….

Epsilon Eridani is the ninth closest star to the Sun. It is slightly smaller and cooler than our own Sun, and is located about 10.5 light-years from Earth in the constellation Eridanus. Epsilon Eridani is visible to the unaided eye, and is younger than the Sun, with an approximate age of 850 million years.

Astronomers say Epsilon Eridani and its planetary system show remarkable similarities to our solar system at a comparable age.

“Studying Epsilon Eridani is like having a time machine to look at our solar system when it was young,” said Smithsonian astronomer Massimo Marengo. Dana Backman from the SETI Institute agreed, saying, “This system probably looks a lot like ours did when life first took root on Earth.” The two astronomers’ paper will appear in the Jan. 10 issue of The Astrophysical Journal.

artist's diagram compares the Epsilon Eridani system to our own solar system. Credit: NASA/JPL/Caltech

As the above image shows, the two systems are structured similarly, and both host asteroids (brown), comets (blue) and planets (white dots). Epsilon Eridani’s inner asteroid belt is located at about the same position as ours, approximately three astronomical units from its star (an astronomical unit is the distance between Earth and the sun.). The system’s second, denser belt lies at about the same place where Uranus orbits in our solar system, or 20 astronomical units from the star. Epsilon Eridani is thought to have planets orbiting near the rims of its two belts. The “Vulcan” –like home world was identified in 2000 via the radial velocity technique. The second planet orbiting near the rim of the outer asteroid belt at 20 astronomical units was inferred when Spitzer discovered the belt. A third planet might orbit in Epsilon Eridani at the inner edge of its outermost comet ring, which lies between 35 and 90 astronomical units. This planet was first hinted at in 1998 due to observed lumpiness in the comet ring.

When the Sun was 850 million years old, theorists calculate that our Kuiper Belt looked about the same as that of Epsilon Eridani. Since then, much of the Kuiper Belt material was swept away, some hurled out of the solar system and some sent plunging into the inner planets in an event called the Late Heavy Bombardment. (The Moon shows evidence of the Late Heavy Bombardment—giant craters that formed the lunar seas of lava called mare.) It is possible that Epsilon Eridani will undergo a similar dramatic clearing in the future.

“Epsilon Eridani looks a lot like the young solar system, so it’s conceivable that it will evolve similarly,” said Marengo.

The Spitzer data show gaps between each of the three rings surrounding Epsilon Eridani. Such gaps are best explained by the presence of planets that gravitationally mold the rings, just as the moons of Saturn constrain its rings.

“Planets are the easiest way to explain what we’re seeing,” stated Marengo.

Future studies may detect these currently unseen worlds, as well as any terrestrial planets that may orbit inside the innermost asteroid belt.

Source: Harvard Smithsonia CfA

October 26, 2008December 24, 2015 by Nancy Atkinson

Manueuver Puts Chandrayaan in Deep Space

Chandrayaan's highly eliptical orbit. Credit: ISRO

After a successful maneuver early today (October 26, 2008), the Chandrayaan-1 spacecraft has crossed the 150,000 km distance mark from Earth, officially entering deep space, on course for the moon. This was the third orbit raising maneuver of the mission. The spacecraft’s 440 Newton liquid engine was fired for about nine and a half minutes, beginning at 07:08 IST. With this, Chandrayaan-1 entered a much higher elliptical orbit around the Earth. The apogee (farthest point from Earth) of this orbit lies at 164,600 km while the perigee (nearest point from Earth) is at 348 km. In this orbit, Chandrayaan-1 takes about 73 hours to go round the Earth once.

To compare, Chandrayaan’s initial orbit had a perigee of 255 km and an apogee of 22,860 km, with about a 6.5-hour period. After the second boost from its engines, Chandrayaan raised its apogee to 37,900 kilometers, and increased its orbit period to 11 hours.

Engineers from the Jet Propulsion Laboratory are also providing backup navigation assistance to the Indian Space Agency in Bangalore, India, by helping to track the flight dynamics. The antennas of the Indian Deep Space Network at Byalalu are being used for tracking and communicating with Chandrayaan-1 spacecraft in its high orbit. From the image below, you can see how additional orbit raising maneuvers in the next few days will take Chandrayaan-1 towards the Moon, and then into lunar orbit. Currently, the spacecraft is scheduled to reach lunar orbit on November 8.

Chandrayaan mission profile. Credit: ISRO

Source: ISRO

October 23, 2008December 24, 2015 by Nancy Atkinson

We All Say “Excited!” In The Same Language

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One of the wonderful things about space exploration and astronomy is how it brings people together across cultures, countries and even languages. Almost all of the current planetary missions — Phoenix, Cassini, and Dawn, for example — are collaborative efforts between scientists and space agencies around the world. And all of our explorations, whether it be through spacecraft or telescopes embody the best of all of humanity: our creativity, our technological advances, our driving curiosity and spirit of perseverance. Furthermore, these explorations excite and inspire us, and also bring us together, providing a common bond. A friend that’s involved with the Chandrayaan mission, (JPL and ISRO working together) that’s now working its way to the Moon, sent me a link to a home video showing Chandrayaan’s launch. You don’t have to speak the language of India to understand how absolutely excited these people were to see their own country’s spacecraft rocket to space. See the video below:

You can’t help but cheer along with the people in the video. We can all cheer, and whoop and holler in excitement in the same language; no translations needed. Congrats to India and all the countries involved in the Chandrayaan mission. Woo hoo! and Yippee!!

October 22, 2008December 24, 2015 by Nancy Atkinson

Where In The Universe Challenge #26

Here’s the image for this week’s “Where In The Universe” challenge. And, like last week, we’ll provide the image, but won’t reveal the answer right away. This gives everyone a chance to mull over the image and provide their answer in the comment section. But check back tomorrow for the answer and to see how you did. Again, here’s the procedure: Take a look at the image above and try to determine where in the universe this image was taken. Give yourself extra points if you can name the spacecraft responsible for taking this image. Post your answers in the comments (if you’re brave enough!) and check back tomorrow for the answer. Good luck!

UPDATE: The answer has now been posted below. If you haven’t made your guess yet, no peeking before you do!!

As the majority of the commenters said, this is Neptune’s moon Triton, taken by Voyager 2. In the summer of 1989, NASA’s Voyager 2 became the first spacecraft to observe the planet Neptune, its final planetary target. Passing about 4,950 kilometers (3,000 miles) above Neptune’s north pole, Voyager 2 made its closest approach to any planet since leaving Earth 12 years earlier. Five hours later, Voyager 2 passed about 40,000 kilometers (25,000 miles) from Neptune’s largest moon, Triton, the last solid body the spacecraft will have an opportunity to study.

Good job, everyone!

October 22, 2008December 24, 2015 by Nancy Atkinson

India’s Chandrayaan-1 On Its Way to the Moon

Artists rendition of Chandrayaan-1 in lunar orbit. Credit: ESA

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Chandrayaan-1, India’s first mission to the Moon, was successfully launched earlier this morning from the Satish Dhawan Space Centre (SHAR) in Sriharikota, India. The PSLV-C11 rocket lifted off at 02:52 Central European Summer Time (CEST). About 20 minutes later the spacecraft was , injected into a highly elongated orbit around the Earth. The spacecraft will reach the moon in about two weeks. It will take several days for the Chandrayaan-1 to reach its lunar transfer orbit, and then it will take about 5 days to reach the moon. Once the spacecraft is orbiting the moon, it will progressively lower its altitude through propulsive maneuvers to reach its final 100 km-high circular orbit.

Chandrayaan-1 mission profile. Credit: ESA

Chandrayaan-1 is a truly international mission, with payloads from Europe as well as the United States. NASA’s contribution includes the Moon Mineralogy Mapper, designed to look for lunar mineral resources, and an instrument known as Mini-SAR, which will look for ice deposits in the moon’s polar regions. Engineers from the Jet Propulsion Laboratory are also providing backup navigation assistance to the Indian Space Agency in Bangalore, India.

At the earliest opportunity, the spacecraft will eject the ‘Moon Impact Probe’ to provide information about the lunar surface. The mission will then continue from orbit, with remote-sensing studies carried out by its 11 scientific instruments. Three of these instruments were provided by Europe (UK, Germany, Sweden) through ESA.

Sources: ESA,

October 20, 2008December 24, 2015 by Nancy Atkinson

Phoenix Lander May Have Been Blasted by Dust Devil

Phoenix's Telltale. Credit: NASA/JPL/Caltech/U of AZ

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A series of images put together to form a movie of the Mars Phoenix lander’s telltale instrument show the telltale waving wildly in the Martian wind. According to Phoenix scientists, movement in one image seemed to be “out-of-phase” with other images, possibly indicating a dust devil whirled nearby or even over the lander. Preliminary analysis of the images taken right before and after the passing of this possible dust devil indicates winds from the west at 7 meters per second. The image taken during the possible dust devil shows 11 meters per second wind from the south.

These images were taken by the lander’s Surface Stereo Imager (SSI) on the 136th Martian day, or sol, of the mission (Oct. 12, 2008). Documenting the telltale’s movement helps mission scientists and engineers determine what the wind is like on Mars. The telltale was built by the University of Aarhus, Denmark, and is part of the lander’s Meteorological Station (MET), developed by the Canadian Space Agency.

Also, Phoenix’s robotic arm successfully delivered soil into oven six of the lander’s thermal and evolved-gas analyzer (TEGA) on Monday, Oct. 13, or Martian day (sol) 137 of the mission.

Six of eight ovens have been used to date.

TEGA’s tiny ovens heat the soil to as high as 1,800 degrees Fahrenheit (1,000 degrees Celsius). The lab’s or mass spectrometer analyzes the gases derived from heating the soil. Mission scientists will continue to research and analyze the soil samples in the coming months, long after Phoenix stops operating on the surface.

Phoenix is gradually getting less power as the sun drops below the horizon.

“My entire team is working very hard to make use of the power we have before it disappears,” said William Boynton of the University of Arizona, Tucson, the lead scientist for TEGA. “Every time we fill an oven, we potentially learn more about Mars’ geochemistry.”

Source: Phoenix News Site

October 20, 2008December 24, 2015 by Nancy Atkinson

Did Lightning and Volcanoes Spark Life on Earth?

Chilean Volcano in 2008 creates lightning. Credit: AP

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Maybe the fictional Dr. Frankenstein wasn’t so crazy after all. Two scientists have resurrected an old experiment, breathing life into a “dead” notion about how life began on our planet. New analysis shows that lightning and gases from volcanic eruptions could have given rise to the first life on Earth.

“It’s alive!”…

Back in the early 1950s, two chemists Stanley Miller and Harold Urey of the University of Chicago did an experiment that tried to recreate the conditions of a young Earth to see how the building blocks of life could have arisen. They used a closed loop of glass chambers and tubes with water and different mixes of hydrogen, ammonia, and methane; the gases thought to be in Earth’s atmosphere billions of years ago. Then they zapped the mixture with an electrical current, to try and confirm a hypothesis that lightning may have triggered the origin of life. After a few days, the mixture turned brown.
When Miller analyzed the water, he found it contained amino acids, which are the building blocks of proteins — life’s toolkit. The spark provided the energy for the molecules to recombine into amino acids, which rained out into the water. The experiment showed how simple molecules could be assembled into the more complex molecules necessary for life by natural processes, like lightning in Earth’s primordial atmosphere.

But there was a problem. Theoretical models and analyses of ancient rocks eventually convinced scientists that Earth’s earliest atmosphere was not rich in hydrogen, so many researchers thought the experiment wasn’t an accurate re-creation of early Earth. But the experiments performed by Miller and Urey were ground-breaking.

“Historically, you don’t get many experiments that might be more famous than these; they re-defined our thoughts on the origin of life and showed unequivocally that the fundamental building blocks of life could be derived from natural processes,” said Adam Johnson, a graduate student with the NASA Astrobiology Institute team at Indiana University, Bloomington. Johnson is the lead author on a paper that resurrects the old origin-of-life experiments, with some tantalizing new findings.

Miller died in 2007. Two former graduate students of Miller’s –geochemists Jim Cleaves of the Carnegie Institution of Washington (CIW) in Washington, D.C., and Jeffrey Bada of Indiana University, Bloomington–were examining samples left in Miller’s lab. They found the vials of products from the original experiment and decided to take a second look with updated technology. Using extremely sensitive mass spectrometers at NASA’s Goddard Space Flight Center Cleaves, Bada, Johnson and colleagues found traces of 22 amino acids in the experimental residues. That is about double the number originally reported by Miller and Urey and includes all of the 20 amino acids found in living things.

Miller actually ran three slightly different experiments, one of which injected steam into the gas to simulate conditions in the cloud of an erupting volcano. “We found that in comparison to Miller’s classic design everyone is familiar with from textbooks, samples from the volcanic apparatus produced a wider variety of compounds,” said Bada.

This is significant because thinking on the composition of Earth’s early atmosphere has changed. Instead of being heavily laden with hydrogen, methane, and ammonia, many scientists now believe Earth’s ancient atmosphere was mostly carbon dioxide, carbon monoxide, and nitrogen. But volcanoes were active during this time period, and volcanoes produce lightning since collisions between volcanic ash and ice particles generate electric charge. The organic precursors for life could have been produced locally in tidal pools around volcanic islands, even if hydrogen, methane, and ammonia were scarce in the global atmosphere.

So, this breathes life into the notion of lightning jump-starting life on Earth. Although Earth’s primordial atmosphere was not hydrogen-rich, gas clouds from volcanic eruptions did contain the right combination of molecules. Is it possible that volcanoes seeded our planet with life’s ingredients? While no one knows what happened next, the researchers are continuing their experiments in an attempt to determine if volcanoes and lightning are the reasons we’re here.

The paper was published in Science on Oct. 17, 2008

Sources: NASA, ScienceNOW

October 19, 2008December 24, 2015 by Nancy Atkinson

New Eye on the Outer Solar System Launches Successfully

The Interstellar Boundary Explorer. Credit: NASA

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There’s a new spacecraft in Earth orbit, with a really “far out” mission: to map the outer solar system. NASA’s Interstellar Boundary Explorer mission, or IBEX launched successfully from the Kwajalein Atoll in the Pacific Ocean at 1:47 p.m. EDT, Sunday, from an Orbital Sciences Pegasus XL launch vehicle. IBEX will be the first spacecraft to image and map dynamic interactions taking place in the outer solar system. The two Voyager probes sent back a limited amount of information about the region of space where our solar system ends and interstellar space begins. But beyond that, not much is known about this area. The region is about three times further from the sun than the orbit of ~~planet~~ Pluto. “No one has seen an image of the interaction at the edge of our solar system where the solar wind collides with interstellar space,” said IBEX Principal Investigator David McComas of the Southwest Research Institute in San Antonio. “We know we’re going to be surprised.”

The spacecraft separated from the third stage of its Pegasus launch vehicle at 1:53 p.m. and immediately began powering up components necessary to control onboard systems. The operations team is continuing to check out spacecraft subsystems.

“After a 45-day orbit raising and spacecraft checkout period, the spacecraft will start its exciting science mission,” said IBEX mission manager Greg Frazier of NASA’s Goddard Space Flight Center in Greenbelt, Md.

“The heliosphere’s boundary region is enormous, and the Voyager crossings of the termination shock, while historic, only sampled two tiny areas 10 billion miles (16 billion km) apart,” NASA scientist Eric Christian said.

Voyager 1 passed the inner boundary in 2004 and Voyager 2 crossed over last year.

The solar wind, a stream of electrically conducting gas continuously moving outward from the sun at 1 million mph (1.6 million kph), blows against this interstellar material and forms a huge protective bubble around the solar system. This bubble is called the heliosphere.

As the solar wind reaches far beyond the planets to the solar system’s outer limits, it encounters the edge of the heliosphere and collides with interstellar space. A shock wave is present at this boundary.

“Every six months, we will make global sky maps of where these atoms come from and how fast they are traveling. From this information, we will be able to discover what the edge of our bubble looks like and learn about the properties of the interstellar cloud that lies beyond the bubble,” physicist Herb Funsten of the U.S. Department of Energy’s Los Alamos National Laboratory.

Sources: NASA, Reuters

October 17, 2008December 24, 2015 by Nancy Atkinson

Fermi Telescope Makes First Big Discovery: Gamma Ray Pulsar

The pulsar lies in the CTA 1 supernova remnant in Cepheus. Credit: NASA/S. Pineault, DRAO

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NASA’s Fermi Gamma-ray Space Telescope discovered the first pulsar that beams only in gamma rays. A pulsar is a rapidly spinning neutron star, the crushed core left behind when a massive sun explodes. Astronomers have cataloged nearly 1,800 pulsars. Although most were found through their pulses at radio wavelengths, some of these objects also beam energy in other forms, including visible light and X-rays. However, this new object only pulses at gamma-ray energies. “This is the first example of a new class of pulsars that will give us fundamental insights into how these collapsed stars work,” said Stanford University’s Peter Michelson, principal investigator for Fermi’s Large Area Telescope.

The gamma-ray-only pulsar lies within a supernova remnant known as CTA 1, which is located about 4,600 light-years away in the constellation Cepheus. Its lighthouse-like beam sweeps Earth’s way every 316.86 milliseconds. The pulsar, which formed about 10,000 years ago, emits 1,000 times the energy of our sun.

“We think the region that emits the pulsed gamma rays is broader than that responsible for pulses of lower-energy radiation,” explained team member Alice Harding at NASA’s Goddard Space Flight Center in Greenbelt, Md. “The radio beam probably never swings toward Earth, so we never see it. But the wider gamma-ray beam does sweep our way.”

Scientists think CTA 1 is only the first of a large population of similar objects.

“The Large Area Telescope provides us with a unique probe of the galaxy’s pulsar population, revealing objects we would not otherwise even know exist,” says Fermi project scientist Steve Ritz, also at Goddard.

Watch an animation of pulsar.

Fermi’s Large Area Telescope scans the entire sky every three hours and detects photons with energies ranging from 20 million to more than 300 billion times the energy of visible light. The instrument sees about one gamma ray every minute from CTA 1, enough for scientists to piece together the neutron star’s pulsing behavior, its rotation period, and the rate at which it is slowing down.

The pulsar in CTA 1 is not located at the center of the remnant’s expanding gaseous shell. Supernova explosions can be asymmetrical, often imparting a “kick” that sends the neutron star careening through space. Based on the remnant’s age and the pulsar’s distance from its center, astronomers believe the neutron star is moving at about a million miles per hour — a typical speed.

Source: NASA

October 16, 2008December 24, 2015 by Nancy Atkinson

Even Early Galaxies Had Supermassive Black Holes

Artist’s conception of the 4C60.07 system of colliding galaxies. Credit: David A. Hardy/UK ATC

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We’re learning more about black holes and the early universe all the time, with the help of all the amazing ground-based telescopes astronomers now have at their disposal. Astronomers think that many – perhaps all – galaxies in the universe contain massive black holes at their centers. New observations with the Submillimeter Array now suggest that such colossal black holes were common even 12 billion years ago, when the universe was only 1.7 billion years old and galaxies were just beginning to form. The new conclusion comes from the discovery of two distant galaxies, both with black holes at their centers, which are involved in a spectacular collision.

4C60.07, the first of the galaxies to be discovered, came to astronomers’ attention because of its bright radio emission. This radio signal is one telltale sign of a quasar – a rapidly spinning black hole that is feeding on its home galaxy.

When 4C60.07 was first studied, astronomers thought that hydrogen gas surrounding the black hole was undergoing a burst of star formation, forming stars at a remarkable rate – the equivalent of 5,000 suns every year. This vigorous activity was revealed by the infrared glow from smoky debris left over when the largest stars rapidly died.

The latest research, using the keen vision of the Submillimeter Array of eight radio antennas located in Hawaii, revealed a surprise. 4C60.07 is not forming stars after all. Indeed, its stars appear to be relatively old and quiescent. Instead, prodigious star formation is taking place in a previously unseen companion galaxy, rich in gas and deeply enshrouded in dust, which also has a colossal black hole at its center.

“This new image reveals two galaxies where we only expected to find one,” said Rob Ivison (UK Astronomy Technology Centre), lead author of the study that will be published in the Monthly Notices of the Royal Astronomical Society. “Remarkably, both galaxies contain supermassive black holes at their centers, each capable of powering a billion, billion, billion light bulbs. The implications are wide-reaching: you can’t help wondering how many other colossal black holes may be lurking unseen in the distant universe.”

Due to the finite speed of light, we see the two galaxies as they existed in the distant past, less than 2 billion years after the Big Bang. The new image from the Submillimeter Array captures the moment when 4C60.07 ripped a stream of material from its neighboring galaxy, as shown in the accompanying artist’s conception. By now the galaxies have merged to create a football-shaped elliptical galaxy. Their black holes are likely to have merged and formed a single, more massive black hole.

The galaxies themselves show surprising differences. One is a dead system that has formed all of its stars already and used up its gaseous fuel. The second galaxy is still alive and well, holding plenty of dust and gas that can form new stars.

“These two galaxies are fraternal twins. Both are about the size of the Milky Way, but each one is unique,” said Steve Willner of the Harvard-Smithsonian Center for Astrophysics, a co-author of the paper.

“The superb resolution of the Submillimeter Array was key to our discovery,” he added.

Source: Smithsonian CfA