Astronomy |

02May 2013

Meteorites May Reveal Mars’ Secrets of Life

In an effort to determine if conditions were ever right on Mars to sustain life, a team of scientists, including a Michigan State University professor, has examined a meteorite that formed on the red planet more than a billion years ago.

And although this team’s work is not specifically solving the mystery, it is laying the groundwork for future researchers to answer this age-old question.

The problem, said MSU geological sciences professor Michael Velbel, is that most meteorites that originated on Mars arrived on Earth so long ago that now they have characteristics that tell of their life on Earth, obscuring any clues it might offer about their time on Mars.

“These meteorites contain water-related mineral and chemical signatures that can signify habitable conditions,” he said. “The trouble is by the time most of these meteorites have been lying around on Earth they pick up signatures that look just like habitable environments, because they are. Earth, obviously, is habitable.

“If we could somehow prove the signature on the meteorite was from before it came to Earth, that would be telling us about Mars.”

Specifically, the team found mineral and chemical signatures on the rocks that indicated terrestrial weathering – changes that took place on Earth. The identification of these types of changes will provide valuable clues as scientists continue to examine the meteorites.

“Our contribution is to provide additional depth and a little broader view than some work has done before in sorting out those two kinds of water-related alterations – the ones that happened on Earth and the ones that happened on Mars,” Velbel said.

Image Credit: Michigan State University

The meteorite that Velbel and his colleagues examined – known as a nakhlite meteorite – was recovered in 2003 in the Miller Range of Antarctica. About the size of a tennis ball and weighing in at one-and-a-half pounds, the meteorite was one of hundreds recovered from that area.

Velbel said past examinations of meteorites that originated on Mars, as well as satellite and Rover data, prove water once existed on Mars, which is the fourth planet from the sun and Earth’s nearest Solar System neighbor.

“However,” he said, “until a Mars mission successfully returns samples from Mars, mineralogical studies of geochemical processes on Mars will continue to depend heavily on data from meteorites.”

Velbel is currently serving as a senior fellow at the Smithsonian Institution’s National Museum of Natural History in Washington D.C.

The research is published in Geochimica et Cosmochimica Acta (citation below), a bi-weekly journal co-sponsored by two professional societies, the Geochemical Society and the Meteoritical Society.

Source: Michigan State University

Reference:

Stopar, J., Taylor, G., Velbel, M., Norman, M., Vicenzi, E., & Hallis, L. (2013). Element abundances, patterns, and mobility in Nakhlite Miller Range 03346 and implications for aqueous alteration Geochimica et Cosmochimica Acta, 112, 208-225 DOI: 10.1016/j.gca.2013.02.024

25Apr 2013

Newborn Stars and their Effect on the Universe

Jason Carr ⋅ 3 Comments

When galaxies form new stars, they sometimes do so in frantic episodes of activity known as starbursts. These events were commonplace in the early Universe, but are rarer in nearby galaxies.

During these bursts, hundreds of millions of stars are born, and their combined effect can drive a powerful wind that travels out of the galaxy. These winds were known to affect their host galaxy — but this new research [Paper here - PDF] now shows that they have a significantly greater effect than previously thought.

An international team of astronomers observed 20 nearby galaxies, some of which were known to be undergoing a starburst. They found that the winds accompanying these star formation processes were capable of ionizing [1] gas up to 650 000 light-years from the galactic center — around twenty times further out than the visible size of the galaxy. This is the first direct observational evidence of local starbursts impacting the bulk of the gas around their host galaxy, and has important consequences for how that galaxy continues to evolve and form stars.

“The extended material around galaxies is hard to study, as it’s so faint,” says team member Vivienne Wild of the University of St. Andrews. “But it’s important — these envelopes of cool gas hold vital clues about how galaxies grow, process mass and energy, and finally die. We’re exploring a new frontier in galaxy evolution!”

The team used the Cosmic Origins Spectrograph (COS) instrument [2] on the NASA/ESA Hubble Space Telescope to analyze light from a mixed sample of starburst and control galaxies. They were able to probe these faint envelopes by exploiting even more distant objects — quasars, the intensely luminous centers of distant galaxies powered by huge black holes. By analyzing the light from these quasars after it passed through the foreground galaxies, the team could probe the galaxies themselves.

“Hubble is the only observatory that can carry out the observations necessary for a study like this,” says lead author Sanchayeeta Borthakur, of Johns Hopkins University. “We needed a space-based telescope to probe the hot gas, and the only instrument capable of measuring the extended envelopes of galaxies is COS.”

The starburst galaxies within the sample were seen to have large amounts of highly ionized gas in their halos — but the galaxies that were not undergoing a starburst did not. The team found that this ionization was caused by the energetic winds created alongside newly forming stars.

This has consequences for the future of the galaxies hosting the starbursts. Galaxies grow by accreting gas from the space surrounding them, and converting this gas into stars. As these winds ionize the future fuel reservoir of gas in the galaxy’s envelope, the availability of cool gas falls — regulating any future star formation.

“Starbursts are important phenomena — they not only dictate the future evolution of a single galaxy, but also influence the cycle of matter and energy in the Universe as a whole,” says team member Timothy Heckman, of Johns Hopkins University. “The envelopes of galaxies are the interface between galaxies and the rest of the Universe — and we’re just beginning to fully explore the processes at work within them.”

Source: ESA/Hubble Information Centre

Notes

[1] A gas is said to be ionised when its atoms have lost one or more electrons — in this case by energetic winds exciting galactic gas and knocking electrons out of the atoms within.

[2] Spectrographs are instruments that break light into its constituent colours and measure the intensity of each colour, revealing information about the object emitting the light — such as its chemical composition, temperature, density, or velocity.

Reference:

Sanchayeeta Borthakur, Timothy Heckman, David Strickland, Vivienne Wild, & David Schiminovich (2013). The Impact of Starbursts on the Circumgalactic Medium The Astrophysical Journal arXiv: 1303.1183v2

01Jan 2013

Reaching E.T. Through Standardized Protocols

Jason Carr ⋅ 15 Comments

Image Credit: SPDO/TDP/DRAO/Swinburne Astronomy

Choosing a single telecommunications protocol has always been difficult for engineers on Earth, so it’s especially difficult for those who want to communicate with beings from another star system. While it’s nice to imagine that extraterrestrial beings would be able to interface with whatever protocol humans decide to encode a message in, that’s not a realistic way to think. Humanity has developed countless electronic communication technologies since the 19th century. There’s no reason to believe that extraterrestrial beings haven’t done the same thing.

SETI and METI organizations have developed a single protocol for sending messages to potential examples of intelligent life. There’s no way of knowing if another civilization could ever actually interpret these signals but the odds are at least a little better with standardized systems.

Imagine an engineer trying to decode a data transmission that no one had ever encountered before. They’d probably try to compare it to other transmissions sent with the same protocol, and then look for the symbols that appear the most. These symbols are probably encoding the most common glyphs in the written language that the transmission represents.

Now imagine that each transmission that the engineer encounters is in a different code. There’s no way for them to compare different messages, because there aren’t any similarities between the different protocols. By using a single system, Earthlings are giving extraterrestrial cultures a chance to decode messages by comparing them to one another. It wouldn’t have been possible for international communications to be achieved on Earth if everyone decided to use their own technology standards.

In fact, poor choices in the past have hampered many types of technological developments. If standardization had occurred between Earthbound transmission sites years ago, these problems would never have reared their ugly head. For that matter, extraterrestrials might very well have been able to intercept numerous types of incidental transmissions. If signals are as weak as one might expect them to be, every little bit matters when we’re talking about communicating across the universe.

If standardization is important, the types of signals sent are equally important (if not more so). Most scientists agree that radio waves are the best way to communicate with other planets/stars given our current level of knowledge. This is due to the fact that radio waves are able to traverse the vast distances involved in actually reaching other stars/planets outside the Milky Way galaxy. Even the closest stars are about 6 light-years away (each light-year is roughly 6 trillion miles). This means that any signals we send their way have to cut through enormous amounts of gas and other obstructions found in space. Radio waves are able to do this effectively (as opposed to say, lightwaves) while traveling vast distances at the speed of light. I have read the work of some scientists that believe lasers may be a good way to reach extraterrestrials as well. I personally feel this is a great alternative to microwaves alone.

While standardization and appropriate signal types are invaluable, they’re also practical because they help to reduce costs. While practicality isn’t something that most people like to discuss, it’s actually pretty necessary in the world of SETI/METI. Many of these organizations, such as the SETI Institute (SETI Institute listens for signals vs. transmitting signals), survive on public donations. They need to maximize what they get out of the financial resources that they’re given to work with. Developing a single standard algorithm helps to reduce the amount of money spent on research while maximizing the chances of success (choosing the right type of signal to send) are crucial to long-term survival. It also means that different pieces of equipment will always interface properly. This means that expensive converts/integrations won’t ever be necessary as long as everyone adheres to the existing standard.

From an engineering standpoint, these groups might want to look at their antennas and transmission sites next (in terms of standardization). Once protocols are standardized, they can begin to improve in other areas as well. Each little bit matters when trying to talk to someone that may exist on a planet that is trillions of miles away.

Reference:

Atri, D., DeMarines, J., & Haqq-Misra, J. (2011). A protocol for messaging to extraterrestrial intelligence Space Policy, 27 (3), 165-169 DOI: 10.1016/j.spacepol.2011.01.001

Edmondson, W. (2010). Targets and SETI: Shared motivations, life signatures and asymmetric SETI Acta Astronautica, 67 (11-12), 1410-1418 DOI: 10.1016/j.actaastro.2010.01.017

21Sep 2012

Radio Astronomy Equipment

Jason Carr ⋅ 1 Comment

Low noise RF filters have already changed radio astronomy quite a bit. However, they’ve usually been based around regular commercial, multi-stage receiver technology. Radio devices have progressed a great deal, especially considering the fact that the transistor has made them so much smaller. Custom designed components would have a number of benefits as well.

This isn’t to say that countless custom designs aren’t in service already. RF devices have simply developed along a certain path. This has allowed discoveries found in one scientific field to be used in many others. While this sort of system is beneficial, it has also forced many researchers to prefer developing components that could be used for countless applications.

Recommended Resource: Society of Amateur Radio Astronomers
Recommended Project: Build Your Own Radio Telescope

Adventurous experimenters might want to try their hand at radio astronomy. They might feel they have nothing to lose. Taking a few proper safety and legal precautions are a must in the field. Some technology is not supposed to be used without a license, especially if it can transmit a signal. Reception of certain signals also might be unlawful. So be careful!

Nevertheless, home experimenters have pushed the boundaries of science in many ways. Hobbyists don’t have to worry about research grants or political motives. That means they might be the ones discovering quasars in the near future.

Image Credit: http://www.kolumbus.fi/michael.fletcher/ra_test.htm

Additional Learning Resources:

30Aug 2012

Stargazing with Open Source Software

Jason Carr ⋅ 2 Comments

While some of you may already run some version of Celestia on your computer, if you’re not, I encourage you to give it a try. Software download directories are regularly listing Celestia’s newer beta releases as they emerge and this particular program has really improved in recent years. Those of you that are using the software currently are likely checking out these releases already. Regular users should probably stick to the traditional version of Celestia, though you might want to check out Celestia Portable if you’re looking for a bit more flexibility in terms of portability. If Celestia isn’t your thing, you might be interested in some of the other planetarium software available out there as well.

Click HERE for links to Celestia software if you’d like to give it a whirl.

Anyone who uses open source software is used to having to download dependencies. Users such as myself spend a lot of time getting software situated just the way we like it. For instance, you might have some stars or trans-Neptunian objects marked so you can easily visit them again. It would be nice to bring these options anywhere you went, right? Portable software allows you to do this very thing. While you still might get stuck downloading dependencies from time to time, Celestia Portable enables you to carry your installation around with you on a thumb drive which is pretty cool. You don’t even have to reinstall it on other computers.

Fans of either the regular Celestia program or its portable cousin might want to have a look at Bing Maps as well. They’ve recently added some astronomy functions, and these can be entertaining for a period of time.

28Aug 2012

Lawrence Henderson’s Views Examined

Jason Carr ⋅ Leave a Comment

Professor Lawrence J. Henderson (1878-1942)

Professor Lawrence J. Henderson is a fairly well known scholar in some circles. This might have to do with the fact that his lecture on astronomy was included in the Harvard Classics (1909-14). That work has now passed into the public domain, which means that readers might start to explore his work once more.

As a side note, if you haven’t read the Harvard Classics, you should do so when you have a chance. They offer keen insights within a historical context that you might not get elsewhere.

Click HERE to read some of Professor Henderson’s work.

Henderson’s personal opinions on astronomy are rather interesting when viewed through a cosmist lens. According to him, astronomy helped to shape the modern intellect. Medieval beliefs that placed the Earth as the center of the universe were eliminated by the discipline of science. This statement is compatible with cosmist ideology, and it supports the idea that astronomy helped to achieve a greater human understanding.

Students of history might take exception with his attitude, however. One could argue that astronomy is the oldest science. Cro-Magnon man surely looked up at the stars. Geocentrism isn’t necessarily a superstitious thought. While it’s incorrect, it’s not a bad scientific theory considering what early astronomers had to work with. Objects apparently orbit this planet, so it’s quite natural they they assumed that the Earth is the center of the solar system. These differences of opinion illustrate the rather schismatic nature of cosmist philosophy.

22Aug 2012

The Murchison Meteorite Revisited

Jason Carr ⋅ 1 Comment

Piece of the Murchison meteorite

While it took researchers years to prove it, the Murchison meteorite had a number of extraterrestrial organic compounds in it. Four decades is a long time when it comes to space exploration. Forty years is a long time to do anything for that matter. However, this is a serious triumph for science.

The highest concentrations of these extraterrestrial molecules ever recorded were found in the Murchison meteorite. People are naturally going to debate back and forth what this means. Some individuals will probably use it for proof of an otherworldly primordial soup synthesis. Others will say that it’s proof of life on other planets.

In reality, this research proves nothing. It suggests that either of those two theories could be true, but more research is necessary before drawing conclusions. If anything, the Murchison case study proves the value of this sort of research. Most organizations would probably like to see new studies regarding the organic material present in current asteroid collections.

While groups like SETI aren’t often invited to the normal academic’s table, they could very easily analyze many of these studies themselves. The information is readily available. Academic research portals now provide easy access to asteroid statistics and the like. It just takes one person to start sifting through it.

14Aug 2012

Christiaan Huygens: Early Astronomer

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Christiaan Huygens (1629-1695) was a Dutch polymath who is well known in some circles to this day. While he spent some time in France and England, Huygens lived the latter portion of his life in his native Holland. Having commented on religion while living in many different countries, Huygens espoused a personal philosophy similar to many aspects of modern science.

The modern pendulum clock was among his more illustrious inventions. Horology is the study of measuring time, and it became something of an obsession for him. Nevertheless, he’s also well remembered among astronomers for discovering the moon Titan. His contributions to the field of optics made modern telescope construction possible as well.

While his calculations regarding stellar distances weren’t always accurate, they were always interesting. Huygens made a screen facing the sun and from measurements taken with this device, he figured out that the sun was approximately the same intensity as that of Sirius. By taking the angle and diameter of the hole, Huygens surmised that Sirius was 30,000 times further away from the Earth than the sun is. However, Sirius is actually around 500,000 times further away. Huygens didn’t realize that Sirius was several times brighter than the sun. Strangely enough, his calculations were accurate for the data he was working with.

07Aug 2012

Meade LX800 Platform [Review]

Jason Carr ⋅ 7 Comments

Serious astrophotography enthusiasts might want to try out the new LX800 series telescope assemblies from Meade. Trademarked StarLock technology seems to be the biggest selling point of the model. Each time the telescope is slewed to a target, the StarLock technology will lock on to the target and then provide guide corrections automatically. This is certainly an impressive feature by itself, and doesn’t even take that long to learn how to use.

They didn’t skimp on the optics or the mount either. Machines stainless steel construction makes up the bulk of the equatorial mount assembly. Hobbyists who have ever gotten snagged should appreciate the internal cabling. Even the tripod is a new design.

The price tag is every bit as incredible as the unit. Some of the LX800 series telescopes can cost upwards of $12,000. Most amateur astronomers don’t have this kind of money to drop on a single telescope. Even the least expensive versions start around $6,000. To make matters worse, these telescopes are often stuck on backorder. While the Meade LX800 is probably the best residential astrophotography platform on the market, amateur astronomers who want to order one should use careful planning (budget, timing, etc.) before making the leap.

02Aug 2012

Observational Astronomy Drawings

Jason Carr ⋅ 3 Comments

Before everyone strapped a camera to their telescopes, a pencil and paper was the way to go. Sharpening a twig is an easy way to make a smudge stick and turn a small graphite blob into an amazing swirling arm of nebula gases. Many famous astronomers of the past went on to create equally famous notebook entries that featured their unique artistic styles. Observational drawing is both an art and a science.

Some amateur astronomers like to use ink for permanent stars, and pencil in the rest of the objects that they observe. They might wish to produce a composite drawing of each individual object they’ve observed on a previous night. However, patience is a virtue when trying to put otherworldly photons down on paper. Most astronomers are tempted to randomly pepper a scene with stars on more than one occasion during their amateur careers, and the discipline requires a great deal of restraint to avoid doing that.

Galileo’s Astronomical Images – Moon Drawings

Despite the rather low-tech images this effort creates, some people actually combine high technology with their astronomy art. While most mobile devices lack great drawing programs, some PDA units actually come with a high-resolution stylus that’s conducive to observational drawing as well. This practice became so popular that it has generated a little buzz on the Internet in the recent past.

I personally learn things better by writing/drawing things in many cases. If you are the same, drawing the objects you view during your stargazing may be a great way to reinforce your memory of the sights you observe.

Image Credits: Simon Atkinson; University of Minnesota