Universe Today

May 5, 2008December 24, 2015 by Astronomy Cast

Podcast: The End of the Universe Part 2: The End of Everything

Hopefully you’ve all recovered from part 1 of this set, where we make you sad about the future of the humanity, the Earth, the Sun and the Solar System. But hang on, we’re really going to bring you down. Today we’ll look far far forward into the distant future of the Universe, at timescales that we can barely comprehend.

If you haven’t heard it, here’s a link to Part 1.

Click here to download the episode

The End of the Universe Part 2: The End of Everything – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

May 5, 2008December 24, 2015 by Nancy Atkinson

Satellite Views of Deadly Cyclone in Myanmar

The cyclone that ravaged the southeast Asian country of Myanmar over the weekend was an incredibly deadly and destructive storm. News reports say at least 10,000 people were killed, and thousands more were missing as of May 5. Cyclone Nargis made landfall with sustained winds of 130 mph and gusts of 150-160 mph, which is the equivalent of a strong Category 3 or minimal Category 4 hurricane. This was the first cyclone of the 2008 season. Above is an image from NASA’s Terra satellite, and specifically the Moderate Resolution Imaging Spectroradiometer (MODIS.) You can see this storm was a whopper, however, by the time MODIS acquired this image on May 3 at 10:55 am local time the cyclone had lost much of its original strength and was at tropical storm strength. Even more astounding are the images available from MODIS of the landscape of Myanmar both before and after the cyclone hit.

The top image was taken on April 15, 2008, well before the storm and shows a calm landscape where rivers and lakes are visible, as well as the green of vegetation. In the lower image, taken on May 5, the entire coastal plain is flooded. News reports say the agricultural areas have been especially hard hit. But cities as well were affected. For example, RangÃ´n, with a population over 4 million is almost completely surrounded by floods. Several other large cities with populations of 100,000â€“500,000 are also in the area affected by the cyclone.

The MODIS Rapid Response Team has been processing the images as soon as they are available from the spacecraft in order to provide information about the storm and the region.

The blue dot on the globe below marks the Andaman Sea and the area affected by Cyclone Nargis.

Original News Source: NASA’s Earth Observatory

May 5, 2008May 10, 2022 by Nancy Atkinson

Titan’s Hydrocarbon “Sand Dunes

Even before the Cassini spacecraft entered the Saturn system, scientists were predicting that Saturn’s moon Titan would be quite Earth-like. And every image that’s been returned of Titan’s clouds, lakes, rivers, and other landforms is proving them right. In 2005 Cassini’s imaging radar discovered a massive area of sand dunes around Titan’s equatorial region. Although these dark, windblown dunes look much like sand dunes on Earth (they’ve been compared to mountainous drifts of coffee grounds), scientists are finding that the dunes are likely made of organic molecules that are not anything at all like sand.

Titan is known to have massive amounts of hydrocarbons. New observations of Titan’s sand dunes raise the possibility that much of the sand grows from hydrocarbon particulates fallen from Titan’s thick atmosphere. Once on the ground, the particulates join together and become sand grain-size particles.

This process is called sintering â€“ where the particles are heated enough to melt together. Scientist Jason W. Barnes of NASA’s Ames Research Center says that this sintering may produce particles that are about the same size as sand grains – between 0.18-0.25 millimeters, which are perfect for blowing in the wind and drifting into dunes.

So, this process is quite the opposite of what happens to sand on Earth, which comes from silicates, gypsum, or rock that have broken down to finer grains. But on Titan, the small hydrocarbon particulates grow together into larger grains. Barnes says the process is extremely slow, but Titan has been around long enough for this to have occurred.

Based on measurements from Cassini, the dunes are 100-200 meters high and are between 1 and 79 kilometers long. Not all over Titan’s surface has been imaged, but scientists believe up to 20 % of Titan’s surface could be covered by these hydrocarbon dunes.

Original News Source: JPL

May 5, 2008December 24, 2015 by Ian O'Neill

Send Your Name to the Moon

The Lunar Reconnaissance Orbiter - artistic impression (NASA)

Have you ever dreamt of travelling to the Moon? Unfortunately, for the time being, this will be a privilege only for an elite few astronauts and robotic explorers. But NASA has just released news that you will have the opportunity to send your name to the Moon on board their next big Moon mission, the Lunar Reconnaissance Orbiter. So get over to the mission site and send your name that will be embedded into a computer chip, allowing a small part of you to orbit our natural satellite over 360,000 km (220 000 miles) away…

Last month I looked into how long it would take to travel to the Moon and the results were wide-ranging. From an impressive eight hour zip past the Moon by the Pluto mission, New Horizons to a slow spiral route taken by the SMART-1 lunar probe, taking over a year. The next NASA mission, the Lunar Reconnaissance Orbiter (LRO), is likely to take about four days (just a little longer than the manned Apollo 11 mission in July 1969). It is scheduled for launch on an Atlas V 401 rocket in late 2008 and the mission is expected to last for about a year.

Thank goodness we’re not travelling by car, according to the LRO mission facts page, it would take 135 days (that’s nearly 5 months!) to get there when travelling at an average speed of 70 miles per hour.

The LRO is another step toward building a Moon base (by 2020), the stepping stone toward colonizing Mars. The craft will orbit the Moon at an altitude of 50 km (31 miles), taking global data, constructing temperature maps, high-resolution colour imaging and measuring the Moon’s albedo. Of course, like all planetary missions to the Moon and Mars, the LRO will look out for water. As the Moon will likely become mankind’s first extra-terrestrial settlement, looking for the location of Moon water will be paramount when considering possible locations for colonization.

This is all exciting stuff, but what can we do apart from watch the LRO launch and begin sending back data? Wouldn’t it be nice if we could somehow get involved? Although we’re not going to be asked to help out at mission control any time soon, NASA is offering us the chance to send our names to the Moon. But how can this be done? First things first, watch the NASA trailer, and then follow these instructions:

Go to “NASA’s Return to the Moon” page.
Type in your first name and last name.
Click “continue” and download your certificate – your name is going to the Moon!

But how will your name be taken to the Moon? It won’t be engraved into the LRO’s bodywork (although that would have been nice!); it will be held on a microchip embedded into the spaceship’s circuitry. The database of names will be taken on board the LRO and will remain with it for the entire duration of the mission. Anyone who submits their name will be exploring the Moon in their own small way. I’ve signed up (see my certificate, pictured) and you have until June 27, 2008 to do the same.

Will see you on board the LRO!

Sources: LRO mission site, Press release

May 5, 2008April 26, 2016 by Tammy Plotner

IC 2944 – Astrophotography by Ken Crawford

Do you think you’re seeing a Hubble Image? Then think again. Just revealed at last weekend’s NEAF gathering at Rockland College in Suffern, New York, this incredible image of IC 2944 was taken by Ken Crawford at Macedon Ranges Observatory and shows so much more than just pretty sky scenery. In this edition of the Universe Today Astronomy Photo of the week, we’ll take a deeper look into the science behind the picture as you discover an anomaly known as “Thackeray’s Globules”…

The photographic artistry of Ken Crawford takes us on a visual journey ever deeper into the busy star-forming region, IC 2944. While the view of this incredible emission nebula is some 6,000 light years away, Ken’s work takes us directly in for close up views of Thackeray’s Globules in ways that stagger the imagination.

IC 2948 is sprawling cloud of gas and dust that is illuminated and heated by a loose cluster of massive stars known as IC 2944. These stars are much hotter and much more massive than our Sun and their strong stellar winds carve out unique shapes in the noble hydrogen gases. These busy star forming HII regions are home to curious dark masses which we really don’t know a whole lot about – except their association. Dark globules like these have been known since Dutch-American astronomer Bart Jan Bok first began documenting them in 1947 and astronomer A.D. Thackeray first spied the globules in IC 2944 in 1950.

The largest of the globules in IC 2944 could possibly be two separate clouds that appear to partially overlap along our line of sight. Each cloud is nearly 1.4 light-years along its longest dimension and a combination of both clouds contain enough material to equal over 15 solar masses. When you take a closer look, you’ll see the globules appear almost shattered – as if strong forces were pulling them apart. In the case of IC 2944, seeing is believing because when radio astronomers observed the faint hiss of molecules within the globules, they realized Thackeray’s million year old discovery is in constant, aggressive motion, moving along in a supersonic dance. Like a water droplet sprayed against hot metal, this dance may be caused by the powerful ultraviolet radiation from the luminous, massive stars. When the region of glowing hydrogen gas is heated, it expands and streams against these dark masses, causing their annihilation.

According the research done by Bo Reipurth, Patrice Corporon, Michael Olberg and Guillermo Tenorio-Tagle: “We believe that the globules are the remnants of an elephant-trunk observed from behind, originating as a Rayleigh-Taylor instability in an expanding neutral shell powered by the hot HII region. The globule complex is now in an advanced stage of disintegration. We have found no evidence for star formation in any of the globules.”

Often known as the Running Chicken Nebula or the Lambda Cen Nebula, IC 2944 and IC 2948 is nestled between the Southern Cross and the star-thick Carina area on the southern border of Centaurus (RA 11:36.6 Dec -63:02). With an average magnitude of 4.5 and spanning around 75 arc minutes, its collection of bright stars is also referred to as Collinder 249 and was given the designation of Caldwell 100 by Sir Patrick Moore. Don’t expect to see a vision in either eyepiece or binoculars. The cluster is easy… But the nebula is very vague!

Image Details: IC 2944
Taken at: MACEDON RANGES OBSERVATORY
AP130 @ F6 / Paramount ME
Apogee Alta 16803
AstroDon – (5nm Ha & SII) & OIII 3nm Filters
Ha =180 minutes mapped to Green
SII =180 minutes Mapped to Red
OIII = 240 minutes Mapped to Blue
CCDAutoPilot for unattended imaging With MaxDL 4

May 5, 2008December 24, 2015 by Tammy Plotner

Eta Aquarid Meteor Shower Peaks

The awesome image of the meteor was taken by D. Polishook, N. Brosch, & I. Manulis (Tel-Aviv U., Wise Obs.), and Spacegaurd Israel and supplied by NASA.

Having the New Moon on our side may very well increase your chances of catching a well established meteor shower which is now reaching its peak activity time – the Eta Aquarids. No matter where you live or what time zone you observe from, the best time to look for the offspring of Halley’s Comet is over the next few nights during the hours just before dawn.

Although Comet Halley is located in the outer reaches of our solar system at the moment, its visit in 1986 wasn’t the one that left a particularly dense stream of material which may spark activity of up to 70 meteors per hour for lucky observers in the southern hemisphere. But don’t count yourself out if you live in the north! Around 4:00 a.m. the Aquarius constellation is beginning to rise low to the southeast and rates could be as proliferate as an average of one meteor every three or four minutes. Because the constellation of Aquarius is relatively low for northern observers, this means we have at least better chance of spotting those breathtaking Earth grazers!

Comet Halley is responsible for more than just the Eta Aquarids, however. Particles shed during the comet’s slow disintegration over the millennium are distributed along its orbit and Earth passes through these streams three times a year. The Eta Aquarid, the Beta Aquarids (both in May) and the Orionids (during October). When a piece of this debris enters our atmosphere, it is traveling about 66 kilometers per second and can shine as brightly as the stars (3rd magnitude) in the constellation from which it appears to originate.

Although meteors can appear from any point in the sky, your best northern skies bet will be to face generally southeast, gaze roughly halfway up the sky and get as comfortable as possible. A reclining lawn chair makes a wonderful meteor watching companion! Getting as far away as possible from city lights will also increase the amount of meteors you see, while just ordinary binoculars will help reveal the twists and turns of the faint trails invisible to the unaided eye. Don’t be discouraged if you’re clouded out or unable to view at this time. The most wonderful part about the Eta Aquarids are the fact that the stream is very broad and the peak activity is drawn out over a period of activity from April 21 until May 12. Around 3:00 a.m., the meteors will first begin penetrating the ionosphere and there is a possibility of strong trails which could last for several seconds. As Aquarius rises higher and dawn approaches, meteor activity is seen “face on”. Like driving through a snowstorm, the meteors will seem to come at you more quickly and give a more streak-like appearance. For those working on your Astronomical League Meteor Challenge lists, be sure to take notes!

Don’t let anyone discourage you from watching the Eta Aquarids if you have an opportunity. While it isn’t one of the most prolific showers of the year, it is very well established and dark skies will help tremendously during this apparition. It has been my experience over the last 20 or so years to at least see a few during an observing session and come away feeling very happy indeed that I took the time to look for Comet Halley’s children racing by.

Good luck and clear skies…

The awesome image of the meteor was taken by D. Polishook, N. Brosch, & I. Manulis (Tel-Aviv U., Wise Obs.), and Spacegaurd Israel and supplied by NASA.

May 5, 2008December 24, 2015 by Nancy Atkinson

Mission to the Sun

Astronomy — Solar Probe Spacecraft. Credit: NASA/Johns Hopkins University Applied Physics Laboratory

A mission to the sun is difficult stuff. For 30 years scientists and engineers have struggled with developing a spacecraft that could survive the harsh environment close to the sun, but always ended up running into insurmountable technology limitations or blowing the top off the budget. But now the Applied Physics Lab believes they have come up with a plan that will work, and NASA has given them the go-ahead to get a mission ready by 2015. And contrary to the old joke about a mission to the sun, the new Solar Probe won’t have an easy time of it by just heading to the sun at night!

The Solar Probe mission will come within 6.6 million kilometers (4.1 million miles) of the sun to study the streams of charged particles the sun hurls into space. The spacecraft will actually be within the sun’s corona — its outer atmosphere — where the solar wind is produced. At closest approach the Solar Probe will zip past the sun at 210 km (125 miles) per second, protected by a carbon-composite heat shield able to withstand up to 1425 degrees Celsius (2,600 degrees Fahrenheit) and survive blasts of radiation and energized dust at levels not experienced by any previous spacecraft.

The spacecraft will weigh about 1,000 pounds. Preliminary designs include a 2.7 meter (9 feet) diameter, 15 centimeter (6 inches) -thick, carbon-foam-filled solar shield atop the spacecraft body, similar to APL’s MESSENGER spacecraft.

The probe will be solar powered (no problem there!) with two sets of solar arrays that will retract or extend as the spacecraft swings toward or away from the sun during several loops around the inner solar system, making sure the panels stay at proper temperatures and power levels. At its closest passes the spacecraft must survive solar intensity more than 500 times what spacecraft experience while orbiting Earth.

“Solar Probe is a true mission of exploration,” says Dr. Robert Decker, Solar Probe project scientist at APL. “For example, the spacecraft will go close enough to the sun to watch the solar wind speed up from subsonic to supersonic, and it will fly though the birthplace of the highest energy solar particles. And, as with all missions of discovery, Solar Probe is likely to raise more questions than it answers.”

Solar Probe will use seven Venus flybys over nearly seven years to gradually shrink its orbit around the sun, coming as close as 4.1 million miles to the sun, about eight times closer than any spacecraft has come before.

The main goals of the Solar Probe are to determine the structure and dynamics of the sun’s magnetic field, trace the flow of energy that heats the corona and accelerates the solar wind, and explore dusty plasma near the sun and its influence on solar wind and energetic particle formation. This mission will also help us learn more about the sun-Earth relationship.

Original News Source: Eureka Alert

May 4, 2008December 24, 2015 by Ian O'Neill

Searching for Water and Minerals on Mars – Implications for Colonization

A Vastitas Borealis crater plus ice in the north polar region - reconstructed image by HRSC (ESA)

New results from the The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board the Mars Reconnaissance Orbiter (MRO) reveal the mineral composition of the bottom of Chandor Chasma. There is a rich mix of sulfate and pyroxene-containing deposits in this region and the CRISM instrument continues to find deposits of minerals never thought to exist on the planet’s surface. However, the primary mission objective is to find evidence of water, past and present, aiding the hunt for the best location of the first Mars settlements. SETI Institute principal investigator and CRISM scientist Dr Adrian Brown answers some of my questions about CRISM and how the results may be useful for future manned missions to the Red Planet…

Part of my duties as Communications Officer with the Mars Foundation (a non-profit organization for Mars settlement designers) is to contact and interview key mission scientists working on missions that could be useful for getting us closer to realising the first manned settlement on the Red Planet. Dr Adrian Brown is one such scientist; the CRISM instrument is one such mission. CRISM, an advanced spectrometer, has been looking out for the mineral fingerprint of water since 2006. Minerals will have dissolved in ancient liquid water, so looking for the dry remnants of these minerals today will help to reveal the surface conditions of the past. Another mission objective is to characterize present water on Mars, seeing how surface water ice forms and how it varies with the seasons. Dr Brown’s current project is to map the seasonal variations of water ice in the Martian southern polar region.

In a timely news release, the CRISM mission site has announced new results to come from the analysis of the mineral distribution at the bottom of Candor Chasma (pictured), part of the vast Valles Marineris. Candor Chasma is a deep, long and steep-sided valley about 813 km (505 miles) long and has been cited as a possible location for the Hillside Settlement concept as conceived by the Mars Foundation. In fact, this settlement concept was the inspiration behind the first permanent settlement aptly called “Underhill” in Kim Stanley Robinson’s epic novel Red Mars. So, there is obvious interest as to what Candor Chasma can offer the colonists inhabiting the Hillside Settlement with easy access to locally mined minerals.

The CRISM instrument has discovered quantities of sulfate and pyroxene rich deposits in the region, useful for many industrial processes. In our interview, Dr Brown outlined other important minerals that CRISM has found and some of their common uses here on Earth:

“These [minerals] include kaolinite (chinaware is made of this mineral), talc (the main constituent of many soaps) and hydrated silica (perhaps like chert, which Indian knives were carved out from). The small amounts of these minerals means it has been impossible to discover them before CRISM, and previously they were discounted in all our modelling of Mars.” – Dr Adrian Brown, SETI Institute principal investigator and CRISM scientist.

For me, the most revealing part of our conversation was Brown’s estimate on the sheer quantity of water held as ice in the north polar cap. The north pole hides under a 1000 km (620 mile) diameter disk of near-pure water ice (with some impurities like sand and dust, giving a pink hue). This disk is 3 km (1.9 miles) high, holding staggering 2.35 million cubic kilometers of water. That’s enough water to cover the continental US to a depth of 200 meters! Throw in the water that is held at the south pole (a carbon dioxide/water ice disk 300 km in diameter and 2 km high) and we’re looking at the equivalent volume of water ice held in the Greenland ice sheet (or 500 times less than the amount of water in our oceans). It’s not that hard to imagine that if a permanent Mars colony is established, mining operations for water ice would be common.

But it doesn’t stop there; water could also be extracted from the atmosphere. One of Dr Brown’s studies focus on measuring the variation of water ice crystals in the clouds throughout the seasons. There should also be quantities of water vapour in the warmer equatorial regions.

There is also the possibility of extracting water from the permafrost layers below the Martian regolith. The Phoenix Mars lander (set to arrive at the Red Planet on May 25th) will be able to investigate the possibility of sources of frozen water below the surface. Dr Brown also indicated that the observations by the Mars Orbital Camera (on board NASA’s Mars Global Surveyor, lost in November 2006) of apparent gullies may reveal the location of possible sub-surface aquifers (after gushing across the surface) for future colonists to “tap” into (pictured). However, there have been studies that dispute this in favour of dry debris flows creating the gullies, but a definitive answer will not be arrived at until the gullies are analysed in-situ. And if he had the chance, I think Dr Brown would be the first to look into this exciting possibility after I asked him the question: Would you like to go to Mars?

“Of course I would love to travel to Mars, most of all to go to the polar regions and observe them with my own eyes. If I could actually go to the surface of Mars to investigate the fascinating geology of Nili Fossae and Valles Marineris, that would be so awesome. And to visit a gully site and dig behind it to try and find its source… and to witness the cold volcanoes of mud that erupt in the polar cryptic region during springtime… to go and understand these things that have us puzzled at the moment would be so amazing… and of course more questions would be raised, more geological problems unearthed, and the cycle of understanding the Red Planet would continue.” – Dr Adrian Brown

I share his enthusiasm and look forward to more discoveries by CRISM.

For more on Dr Adrian Brown’s work, check out his website: http://abrown.seti.org/

Sources: The Mars Foundation, CRISM

May 2, 2008December 24, 2015 by Ian O'Neill

Could Jupiter Wreck the Solar System?

Could Jupiter throw the planets into eachother? (NASA)

Scientists have expressed their concern that the Solar System may not be as stable as it seems. Happily orbiting the Sun, the eight planets (plus Pluto and other minor planets) appear to have a high degree of long-term gravitational stability. But Jupiter has a huge gravitational influence over its siblings, especially the smaller planets. It appears that the long-term prospects for the smallest planet are bleak. The huge gravitational pull of Jupiter seems to be bullying Mercury into an increasingly eccentric death-orbit, possibly flinging the cosmic lightweight into the path of Venus. To make things worse, there might be dire consequences for Earth…

Jupiter appears to be causing some planetary trouble. This gas giant orbits the Sun at a distance of approximately 5 AU (748 million km), that’s five times further away from the Sun than the Earth. Although the distance may be huge, this 318 Earth-mass planet’s gravitational pull is very important to the inner solar system planets, including tiny Mercury. Mercury orbits the Sun in an elliptical orbit, ranging between 0.47 AU (at aphelion) to 0.31 AU (at perihelion) and is only 0.055 Earth masses (that’s barely five-times the mass of our Moon).

Running long-term simulations on the orbits of our Solar System bodies, scientists in France and California have discovered something quite unsettling. Jacques Laskar of the Paris Observatory, as well as Konstantin Batygin and Gregory Laughlin of the University of California, Santa Cruz have found that Jupiter’s gravity may perturb Mercury’s eccentric orbit even more. So much so their simulation predicts that Mercury’s orbit may extend into the path of Venus; or it might simply fall into the Sun. The researchers formulate four possible scenarios as to what may happen as Mercury gets disturbed:

Mercury will crash into the Sun
Mercury will be ejected from the solar system altogether
Mercury will crash into Venus
Mercury will crash into Earth

The last option is obviously the worst case scenario for us, but all will be bad news for Mercury, the small planet’s fate appears to be sealed. So what’s the likelihood Mercury could crash into the Earth? If it did, the asteroid that most likely wiped out the dinosaurs will seem like a drop in the ocean compared with a planet 4880 km in diameter slamming into us. There will be very little left after this wrecking ball impact.

But here’s the kicker: There is only a 1% chance that these gravitational instabilities of the inner Solar System are likely to cause any kind of chaos before the Sun turns into a Red Giant and swallows Mercury, Venus, Earth and Mars in 7 billion years time. So, no need to look out for death-wish Mercury quite yet… there’s a very low chance that any of this will happen. But some good news for Mars; the researchers have also found that if the chaos does ensue, the Red Planet may be flung out of the Solar System, possibly escaping our expanding Sun. So, let’s get those Mars colonies started! Well, within the next few billions of years anyhow…

These results by Batygin and Laughlin will be published in The Astrophysical Journal.

Source: Daily Galaxy

Here are some facts on Mercury.

May 2, 2008April 26, 2016 by Nancy Atkinson

Happy Space Day!

Itâ€™s the first Friday in May; therefore it must be Space Day! Since 1997 people around the world have used this day to celebrate humankindâ€™s accomplishments in our exploration of space, as well as recognizing the benefits and opportunities that space exploration provides. While anyone can celebrate this occasion, the main goal of Space Day is to â€œpromote math, science, technology and engineering education by nurturing young peoples’ enthusiasm for the wonders of the universe and inspiring them to continue the stellar work of today’s space explorers.â€ So, if you can, spend some time today talking about space and astronomy with a young person. Even better: do a space-related activity together….

The Space Day website has some great information for students, educators and parents and includes activities, games, and educational materials to download. For educators there are lesson plans and an event organizer.

The website even lists 101 Ways To Celebrate Space Day. Some of my favorites are:

#2. Pretend you are a reporter. Write a story about an important event in space exploration history. (I really like this one, and its even better when you donâ€™t have to pretend!)

#23. Make models of craters or volcanoes from other planets. (Both are extremely fun.)

#37. Ask a librarian to help you find books about space exploration. (Librarians are wonderful.)

#101. Celebrate Space Day on the first Friday of May!

Learn more about Space Day here.