Posted on by Jean Tate

Horsehead Nebula

Horsehead Nebula

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The Horsehead nebula is a dark nebula that looks like a horse’s head! It is part of the Orion Molecular Cloud complex, and has the more correct, if boring, name Barnard 33 (being object number 33 in a catalog of dark nebulae, by Barnard).

It is about 1500 light-years away, and is itself dark because of the dust of which it’s made (it’s also made up of gas, in fact it’s mostly gas, but the gas is essentially transparent). What makes it so obvious is the diffuse glow from behind it; the glow is red – due to the Balmer Hα line, a prominent atomic transition in hydrogen – and is powered by the UV light from the nearby star, Sigma Orionis (which is actually a five-star system), which ionizes the hydrogen gas in this part of the Orion Complex.

The first record of its shape is from 1888, by Williamina Fleming, who noticed it on a photographic plate taken at the Harvard College Observatory (Fleming made significant contributions to astronomy, including cataloguing many of the stars in the famous Henry Draper Catalogue). The Horsehead nebula is a favorite of amateur astronomers, especially astrophotographers (it’s quite difficult to spot visually).

The Horsehead nebula is similar to the Pillars of Creation (in M16), though perhaps not as dense; one day it too will be eroded by the intense UV from the young stars in its vicinity, and from new-born stars formed within it (the bright area at the top left is light from just such a star).

In 2001, the Hubble Space Telescope Institute asked the public to vote for an astronomical target for the Hubble Space Telescope to observe, a sort of Universe Idol contest … the Horsehead nebula was the clear winner! Hands up all of you who have, or have had, the Hubble’s image of the Horsehead as your wallpaper, or perhaps the VLT one …

Universe Today has, among its stories, some good background on the Horsehead; for example Dark Knight Ahead – B33 by Gordon Haynes, Astrophoto: The Horsehead Nebula by Filippo Ciferri, and What’s Up This Week – Jan 3 – Jan 9, 2005.

The Astronomy Cast episode Nebulae explains the role of dark nebulae, such as the Horsehead, in starbirth; well worth a listen.

Sources: NASA APOD, Wikipedia

Posted on by Nancy Atkinson

Stunning Cassini Image to Knock Your Socks Off

What a way to start the day! This image is one of the first things I saw online this morning. The moon Rhea hangs like a pendant against Saturn and its rings. Amazingly, this is a raw image straight from Cassini; it has not been calibrated or enhanced in any way. This is art in its purest form and evidence of the phenomenal and enchanting beauty of the Saturn system, as well as confirmation of what an amazing spacecraft Cassini is.

This image was taken on November 08, 2009 and received on Earth November 09, 2009. The camera was pointing toward Rhea at approximately 1,874,061 kilometers away.

Here’s the link to a higher resolution version.

Source page.

Hat tip to @mars_stu on Twitter

Posted on by Nicholos Wethington

Vatican Holds Conference on Extraterrestrial Life

Though it may seem an unlikely location to happen upon a conference on astrobiology, the Vatican recently held a “study week” of over 30 astronomers, biologists, geologists and religious leaders to discuss the question of the existence of extraterrestrials. This follows the statement made last year by the Pope’s chief astronomer, Father Gabriel Funes, that the existence of extraterrestrials does not preclude a belief in God, and that it’s a question to be explored by the Catholic Church. The event, put on by the Pontifical Academy of Sciences, took place at the Casina Pio IV on the Vatican grounds from November 6-11.

The conference was meant to focus on the scientific perspective on the subject of the existence of extraterrestrial life, and pulled in perspectives from atheist scientists and Catholic leaders alike. It was split into eight different segments, starting with a topics about life here on Earth such as the origins of life, the Earth’s habitability through time, and the environment and genomes. Then the detection of life elsewhere, search strategies for extrasolar planets, the formation and properties of extrasolar planets was discussed, culminating in the last segment, intelligence elsewhere and ‘shadow life’ – life with a biochemistry completely different than that found on Earth.

Speakers at the event included notable physicist Paul Davies and Jill C. Tarter, the Director of the Center for SETI Research. Numerous astrobiologists and astronomers researching extrasolar planets also were in attendance to give lectures. The whole series of speech abstracts and a list of participants is available in a brochure on the Vatican site, here.

The event was held to mark the International Year of Astronomy, and the participants hope to collect the lectures into a book. Father Gabriel Funes, the chief astronomer of the Vatican, said in an interview to the Vatican paper, Osservatore Romano last year:

“Just like there is an abundance of creatures on earth, there could also be other beings, even intelligent ones, that were created by God. That doesn’t contradict our faith, because we cannot put boundaries to God’s creative freedom. As saint Francis would say, when we consider the earthly creatures to be our “brothers and sisters”, why couldn’t we also talk about a “extraterrestrial brother”? He would still be part of creation.”

Even with the discovery of over 400 exoplanets, the question of extraterrestrial life still remains to be answered in our own Solar System. It is a pertinent question for the religious and non-religious alike. Though it wasn’t answered at this most recent conference, the existence of life outside what we know here on Earth has an equal impact on the findings of science as it does the meaning of religion. This event certainly brought the two under the same roof for what were surely some interesting and fruitful conversations.

Source: Physorg, Pontifical Academy of Sciences

Posted on by Nancy Atkinson

Good News for Science News

Here’s some refreshing news! In an era when mainstream media is cutting back on their science departments and science reporting, the Discovery Channel has just made an investment to step-up their science news with the re-launch of their new and improved news website, Discovery News. In the middle of it all is our very own Ian O’Neill, who is also the producer for Discovery News Space. The “new” part of Discovery News is that Ian’s work on the space side is now integrated into a higher profile, redesigned news site. Ian and I had a chance to talk today about this good news for science news.

“Discovery News was always the Discovery Channel website’s news source. It has been around for about 11 years,” Ian told me, “and people started coming to the Discovery Channel website specifically to read Discovery News, so it was always like a little news agency bubbling around in the background.”

About 18 months ago Discovery News put together three different “hubs” to focus on space, Earth and technology. Those three headings are now given top billing on the new site, integrating news and blogs together.

Ian and I talked about how Universe Today wears both hats as both a news site and a blog, and Discovery News is doing that as well, but in a bigger way with over 20 correspondents, producers and editors.

“We know we have to have both strong traditional reported items as well as opinion based pieces, and we now have a nice relationship between the two,” Ian said. “Blogging has become a major news source for a lot of people, as a lot of the blogs are now written by science professionals. There doesn’t seem to be that big distinction or chasm anymore between a reported item and what is opinion, and often the two fade in between.”

All the Discovery News contributors have professional backgrounds in their fields, and it’s great to see a “big” company investing in science-based journalism.

“They have created the opportunity for Discovery News to relaunch, and given us the resources to perhaps be a one-of-a kind science news site,” Ian said.

Check out Discovery News.

Posted on by Mark Mortimer

the Bluffer’s Guide to the Cosmos

Bluffer's Guide to the Cosmos

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The English language continually evolves. Just see Ambrose Bierce’s definition of dictionary. New concepts call for new words that often evolve from a new dictum. Astronomy has made its fair share of contributions to this cause. But, Daniel Hudon’s book “The Bluffer’s Guide to: The Cosmos” belies such augmentations. Within, the language is as common and everyday as what you used around the gas pump or barber shop. Yet, the science and information is as exact and appropriate as needed to communicate an idea.

The idea of a bluffer’s guide is, presumably, to allow a reader without formal training to wax eruditely about a particular topic. The Cosmos is, of course, pretty big. In fact it’s about as big as things get from our perspective. Yet, the book’s undaunted brashness allows a reader to become familiar with the heady concepts of cosmology. Its material is current, as noted by the reference to eight planets in our solar system. It’s humorous, as noted by fun sounding words like Zubenelgenubi. And it’s short and sweet, as noted by its small format and brief 86 pages. However, the few pages allow for the book to entertain the reader rather than drown them in details.

The focus on providing for the reader’s entertainment remains a fixture throughout the book. Thus, true to the title’s promise, a reader might be able to bluff their way through a conversation about the Cosmos after having read it. But, this book would better serve those readers who simply want to relate an unknown, difficult sounding subject to their own everyday perceptions. For instance, if the Earth is the size of an apple, then Uranus is the size of a honey dew melon. Or, consider the Big Bang to be like a cosmic burp happening 13.7 billion years ago. With this technique, the book should keep the naïve reader interested and also keep them reading to the end.

With cosmologists continually adding to society’s knowledge base, the everyday person could easily get overwhelmed with new phrases like ‘mysterious energy’. Yet, Daniel Hudon’s book “The Bluffer’s Guide to: The Cosmos” can come to the rescue. It succinctly delivers these ideas into simple, common verbiage and should keep the reader smiling at the same time.

Posted on by Nancy Atkinson

Finding the Mama Bear of Black Holes

While astronomers have studied both big and little black holes for decades, evidence for those middle-sized black holes has been much harder to come by. Now, astronomers at NASA’s Goddard Space Flight Center in Greenbelt, Md., find that an X-ray source in galaxy NGC 5408 represents one of the best cases for a middleweight black hole to date. “Intermediate-mass black holes contain between 100 and 10,000 times the sun’s mass,” explained Tod Strohmayer, an astrophysicist at Goddard. “We observe the heavyweight black holes in the centers of galaxies and the lightweight ones orbiting stars in our own galaxy. But finding the ‘tweeners’ remains a challenge.”

Several nearby galaxies contain brilliant objects known as ultraluminous X-ray sources (ULXs). They appear to emit more energy than any known process powered by stars but less energy than the centers of active galaxies, which are known to contain million-solar-mass black holes.

“ULXs are good candidates for intermediate-mass black holes, and the one in galaxy NGC 5408 is especially interesting,” said Richard Mushotzky, an astrophysicist at the University of Maryland, College Park. The galaxy lies 15.8 million light-years away in the constellation Centaurus.

Artists concept of a medium sized black hole. Credit: NASA
Artists concept of a medium sized black hole. Credit: NASA

XMM-Newton detected what the astronomers call “quasi-periodic oscillations,” a nearly regular “flickering” caused by the pile-up of hot gas deep within the accretion disk that forms around a massive object. The rate of this flickering was about 100 times slower than that seen from stellar-mass black holes. Yet, in X-rays, NGC 5408 X-1 outshines these systems by about the same factor.

Based on the timing of the oscillations and other characteristics of the emission, Strohmayer and Mushotzky conclude that NGC 5408 X-1 contains between 1,000 and 9,000 solar masses. This study appears in the October 1 issue of The Astrophysical Journal.

“For this mass range, a black hole’s event horizon — the part beyond which we cannot see — is between 3,800 and 34,000 miles across, or less than half of Earth’s diameter to about four times its size,” said Strohmayer.

If NGC 5408 X-1 is indeed actively gobbling gas to fuel its prodigious X-ray emission, the material likely flows to the black hole from an orbiting star. This is typical for stellar-mass black holes in our galaxy.

Strohmayer next enlisted the help of NASA’s Swift satellite to search for subtle variations of X-rays that would signal the orbit of NGC 5408 X-1’s donor star. “Swift uniquely provides both the X-ray imaging sensitivity and the scheduling flexibility to enable a search like this,” he added. Beginning in April 2008, Swift began turning its X-Ray Telescope toward NGC 5408 X-1 a couple of times a week as part of an on-going campaign.

Swift detects a slight rise and fall of X-rays every 115.5 days. “If this is indeed the orbital period of a stellar companion,” Strohmayer said, “then it’s likely a giant or supergiant star between three and five times the sun’s mass (1 solar mass is the mass of the Sun).” This study has been accepted for publication in a future issue of The Astrophysical Journal.

The Swift observations cover only about four orbital cycles, so continued observation is needed to confirm the orbital nature of the X-ray modulation.

“Astronomers have been studying NGC 5408 X-1 for a long time because it is one of the best candidates for an intermediate-mass black hole,” adds Philip Kaaret at the University of Iowa, who has studied the object at radio wavelengths but is unaffiliated with either study. “These new results probe what is happening close to the black hole and add strong evidence that it is unusually massive.”

Paper: Evidence for an Intermediate-Mass Black Hole in NGC 5804

Source: NASA

Posted on by Nancy Atkinson

Great Observatories Combine for Stunning Look at Milky Way

All we can say is, “Wow!” In celebration of the International Year of Astronomy 2009, NASA’s Great Observatories — the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory — have collaborated to produce an unprecedented image of the central region of our Milky Way galaxy. This is a never-before-seen view of the turbulent heart of our home galaxy. The image is being unveiled by NASA to commemorate the anniversary of when Galileo first turned his telescope to the heavens in 1609. NASA provided this image and the individual images taken by each of the Great Observatories to more than 150 planetariums, museums, nature centers, libraries, and schools across the country.

In this spectacular image, observations using infrared light and X-ray light see through the obscuring dust and reveal the intense activity near the galactic core. Note that the center of the galaxy is located within the bright white region to the right of and just below the middle of the image. The entire image width covers about one-half a degree, about the same angular width as the full moon.

For more about the image or to download larger versions, go to this page on the HubbleSite.

Posted on by Nancy Atkinson

Hard-Luck Hayabusa In More Trouble

Artist concept of the Hayabusa spacecraft, which visited asteroid Itokawa in 2005 and returned samples to Earth in 2010. Credit: JAXA
Artist concept of the Hayabusa spacecraft, which visited asteroid Itokawa in 2005 and returned samples to Earth in 2010. Credit: JAXA

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A problem-plagued Japanese mission to an asteroid just may have received its final blow. The Haybusa mission, which went to asteroid Itokawa in 2005 is currently trying to return to Earth, but now has suffered a breakdown in the third out of four ion thrusters. The cause was a voltage spike due to problems with a neutralization vessel, which previously caused the failure of two other thrusters. The fourth and only remaining thruster was shutdown earlier by engineers after signs that it also might succumb to high voltage damage. Engineers are now testing that engine, Thruster C, to determine if it is capable of long-duration firings. Hayabusa, which landed on Itokawa (possibly several times – mission managers aren’t sure) might contain samples, but due to a malfunction of the sample collection device, JAXA has acknowledged that it cannot be sure Hayabusa actually managed to take samples from the surface of the asteroid.

Thruster D failed last Wednesday, according to the Japan Aerospace Exploration Agency (JAXA).

Hayabusa’s four experimental microwave discharge ion engines consume xenon gas and expel the ionized propellant at high speeds to produce thrust. Ion engines are more efficient than conventional chemical thrusters because they use less fuel and can operate continuously for thousands of hours. Hayabusa’s thrusters have accumulated almost 40,000 hours of burn time since the probe launched in May 2003.

The spacecraft was originally scheduled to return to Earth in 2007, but the arrival date was pushed back to 2010 following thruster, communications, gyro and fuel-leak problems.

Thruster D had been the lone engine guiding the spacecraft since February 2009. Officials now say they are evaluating the asteroid mission’s return course after last week’s glitch, and will try to re-fire Thruster C in order to obtain the trajectory and speed required for the return to Earth.

Hayabusa spent three months exploring Itokawa in late 2005, taking over 1,600 pictures and collecting near-infrared and X-ray spectral data to investigate the small potato-shaped asteroid’s surface composition.

During a failed sampling attempt in November 2005, Hayabusa made an unplanned landing and spent up to a half-hour on Itokawa, becoming the first spacecraft to take off from an asteroid. The spacecraft attempted to fire a pellet into the asteroid’s surface and retrieve rock samples through a funnel leading to a collection chamber. However, telemetry showed Hayabusa likely did not fire its projectile while on the surface; but scientists were hopeful bits of dust or pebbles found their way through the funnel and into the sample retrieval system.

Source: Spaceflightnow

Posted on by Nancy Atkinson

Carnival of Space #128

This week’s Carnival of Space is hosted over at AARTScope Blog.

Click here to read the Carnival of Space #128.

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let Fraser know if you can be a host, and he’ll schedule you into the calendar.

Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.

Posted on by Nancy Atkinson

New Module for ISS Launches

Soyuz rocket with Poisk. Credit: NASA TV

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A new module for the space station blasted off today from the Baikonur Cosmodrome, Kazakhstan at 9:22 a.m. EST. The Poisk (which means “explore” in Russian) is a combination docking module/airlock/future research module. It will meet up with the ISS on Thursday at 10:44 am. Poisk is the first permanent pressurized module to be added since May of 2008, when the Japanese “JEM” research module became part of the ISS, and is the first major Russian addition to the station since the Pirs docking compartment was launched in 2001. The new module will be used as an additional docking port for Russian vehicles, as an airlock for Russian-based spacewalks and as a platform for external science experiments.

The new module is almost identical in size to Pirs, at 2.5 meters (8 feet wide) and about 4 meters (13 feet) long. Its first use will be as a docking port during the relocation of a Soyuz crew vehicle in January.

About 1,800 pounds of cargo is loaded into Poisk’s pressurized compartment for delivery to the space station.

A companion module, the Mini Research Module-1, will be carried to orbit on space shuttle Atlantis’ STS-132 mission, targeted to launch in May 2010. That module will be robotically attached to the station’s Zarya module.

Source: NASA