A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!
Active Region 1429 unleashed an X5.4-class solar flare early this morning at 00:28 UT, as seen in this image by NASA’s Solar Dynamics Observatory (AIA 304). The eruption belched out a large coronal mass ejection (CME) into space but it’s not yet known exactly how it will impact Earth — it may just be a glancing blow.
Solar flares are categorized by a scale according to their x-ray brightness. X is the strongest class, followed by M and then C-class. Within each class the numbers 1 through 9 subdivide the flares’ intensity.
A run-in with an X5-class flare is a major geomagnetic event that can cause radio blackouts on Earth and disrupt satellite operations, as well as intensify auroral activity.
The GOES satellite data for the March 7 flare is below:
The CME is expected to impact Earth sometime on the 8th or 9th. Check back here or at Spaceweather.com for updates on the storm (and any subsequent aurora photos!)
Also, check out the video below, assembled by the SDO team. Just after the X5.4-class flare another smaller X1-class flare occurred, sending a visible wave cross the Sun.
Image courtesy NASA, SDO and the AIA science team. And thanks to Camilla Corona SDO for all the updates!
In a 2008 interview by TIME magazine, astrophysicist Neil deGrasse Tyson was asked what he thought the “most astounding fact” about the Universe was. Never at a loss for words, the famed scientist gave his equally astounding answer. His response is in the video above, set to images and music by Max Schlickenmeyer.
It’s the best three minutes and thirty-three seconds you’ll spend all day.
Lake Cuitzeo in central Mexico. (Via Julio Marquez, Wikipedia Commons)
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Exotic sediments found beneath the floor of Lake Cuitzeo in central Mexico support theories of a major cosmic impact event 12,900 years ago, report a 16-member international research team. The impact may have caused widespread environmental changes and contributed to the extinctions of many large animal species.
Images of single and twinned nanodiamonds show the atomic lattice framework of the nanodiamonds. Each dot represents a single atom. (Source: UCSB release.)
The team found a 13,000-year-old layer of sediment that contains materials associated with impact events, such as soot, impact spherules and atomic-scale structures known as nanodiamonds. The nanodiamonds found at Lake Cuitzeo are of a variety known as lonsdaleite, even harder than “regular” diamond and only found naturally as the result of impact events.
The thin layer of sediment below Cuitzeo corresponds to layers of similar age found throughout North America, Greenland and Western Europe.
It’s thought that a large several-hundred-meter-wide asteroid or comet entered Earth’s atmosphere at a shallow angle 12,900 years ago, melting rocks, burning biomass and, in general, causing widespread chaos and destruction. This hypothesized event would have occurred just before a period of unusually cold climate known as the Younger Dryas.
The Younger Dryas has been associated with the extinction of large North American animals such as mammoths, saber-tooth cats and dire wolves.
“The timing of the impact event coincided with the most extraordinary biotic and environmental changes over Mexico and Central America during the last approximately 20,000 years, as recorded by others in several regional lake deposits,” said James Kennett, professor of earth science at UC Santa Barbara and member of the research team. “These changes were large, abrupt, and unprecedented, and had been recorded and identified by earlier investigators as a ‘time of crisis.’ ”
The exotic materials found in the sediment beneath Cuitzeo could not have been created by any volcanic, terrestrial or man-made process. “These materials form only through cosmic impact,” Kennett said.
The only other widespread sedimentary layer ever found to contain such an abundance of nanodiamonds and soot is found at the K-T boundary, 65 million years ago. This, of course, corresponds to the impact event that led to the extinction of the dinosaurs.
The researchers’ findings appeared March 5 in the Proceedings of the National Academy of Sciences. Read the news release from UC Santa Barbara here.
A lunar boulder peeks out into the sunlight. (NASA/GSFC/Arizona State University)
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A lunar boulder catches the last edge of the setting sunlight in this image from the Lunar Reconnaissance Orbiter Camera. The boulders litter the floor of an unnamed 3.5 km wide (2.17 mile wide) crater located within the much larger crater Lobachevskiy. The smaller crater’s rim casts its shadow along the left side of the image, and raises the question: why are shadows on the Moon so dark?
On Earth, air scatters light and allows objects not in direct sunlight to be still well-lit. This is an effect called Rayleigh scattering, named for the British Nobel-winning physicist Lord Rayleigh (John William Strutt.) Rayleigh scattering is the reason why the sky is blue, and (for the most part) why you can still read a magazine perfectly well under an umbrella at the beach.
On the Moon there is no air, no Rayleigh scattering. So shadows are very dark and, where sunlight hits, very bright. Shadowed areas are dramatically murky, like in the LROC image above, yet there’s still some light bouncing around in there — this is due to reflected light from the lunar surface itself.
Buzz was well-lit by reflected light, even in Eagle's shadow. (NASA/Apollo Image Archive)
Lunar regolith is composed of fine, angular particles of very reflective dust. It tends to reflect light directly back at the source, and will illuminate objects within shadows as well — as seen in Apollo mission photographs. Astronauts within the shadow of the landing modules were still visible, and their suits were well illuminated by reflected light from the lunar surface. Some people have used this as “proof” that the landings were actually filmed on a sound stage under artificial lights, but in reality it’s all due to reflected light.
So even though air isn’t scattering the sunlight on the Moon, there’s still enough reflection to sneak light into the shadows… but not much. It gets dark — and quickly cold — in there!
And if you’re one of those who likes to get a better look into the shadows, here’s the same image above with the dark areas brightened enough to see details:
Shadow world revealed! (NASA/GSFC/Arizona State University/J. Major)
Some interesting boulder trails in there!
See this image on Arizona State University’s LROC news page here, and zoom into the full NAC scan here.
A waning gibbous moon. Rises after sunset, high in the sky after midnight, visible to the southwest after sunrise. (NASA/GSFC)
As the Moon orbits Earth, it rotates at such a rate as to keep the same face aiming our way… but not exactly the same face, as shown in this excellent video from NASA’s Goddard Space Flight Center (lovingly annotated by the Bad Astronomer himself, Dr. Phil Plait.)
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The Moon has a slight wobble to its axial rotation, and over the course of a month its orientation shifts slightly — an effect called libration. Think of it like a top or gyroscope spinning on a table; it doesn’t spin perfectly vertically, but rather sways a bit while it spins. Libration is that sway.
In addition to that movement, the Moon also moves closer to and further from the Earth over the course of a year due to its elliptical orbit. This makes it appear to change size slightly.
Except for the Moon’s phases, such effects aren’t immediately obvious from one night to the next. But when assembled into a high-resolution video using images and laser altimetry data maps from the Lunar Reconnaissance Orbiter, the monthly motions of the Moon become incredibly clear!
This video shows all the views of the Moon for the entire year of 2012.
Thanks to Phil Plait of Discover Magazine’s Bad Astronomy blog for adding the music and descriptions to the GSFC’s amazing video. What a marvelous night for a Moon dance!
See the current Moon phase and the original video on the Goddard Space Flight Center’s “Dial-A-Moon” page here.
Video: NASA/Goddard Space Flight Center Visualization Studio. Notations by Phil Plait. Music by Kevin MacLeod/incomptech.com.
Cassini has detected molecular oxygen ions around Saturn's icy Dione
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There’s oxygen around Dione, a research team led by scientists at New Mexico’s Los Alamos National Laboratory announced on Friday. The presence of molecular oxygen around Dione creates an intriguing possibility for organic compounds — the building blocks of life — to exist on other outer planet moons.
Dione's signature "wispy lines" are actually the bright walls of long cliff faces. (NASA/JPL/SSI)
One of Saturn’s 62 known moons, Dione (pronounced DEE-oh-nee) is 698 miles (1,123 km) in diameter. It orbits Saturn at about the same distance that our Moon orbits Earth. Heavily cratered and crisscrossed by long, bright scarps, Dione is made mostly of water ice and rock. It makes a complete orbit of Saturn every 2.7 days.
Data acquired during a flyby of the moon by the Cassini spacecraft in 2010 have been found by the Los Alamos researchers to confirm the presence of molecular oxygen high in Dione’s extremely thin atmosphere — so thin, in fact, that scientists prefer the term exosphere.
While you couldn’t take a deep breath on Dione, the presence of O2 indicates a dynamic process in action.
“The concentration of oxygen in Dione’s atmosphere is roughly similar to what you would find in Earth’s atmosphere at an altitude of about 300 miles,” said Robert Tokar, researcher at Los Alamos National Laboratory and lead author of the paper published in Geophysical Research Letters. “It’s not enough to sustain life, but—together with similar observations of other moons around Saturn and Jupiter—these are definitive examples of a process by which a lot of oxygen can be produced in icy celestial bodies that are bombarded by charged particles or photons from the Sun or whatever light source happens to be nearby.”
On Dione the energy source is Saturn’s powerful magnetic field. As the moon orbits the giant planet, charged ions in Saturn’s magnetosphere slam into the surface of Dione, stripping oxygen from the ice on its surface and crust. This molecular oxygen (O2) flows into Dione’s exosphere, where it is then steadily blown into space by — once again — Saturn’s magnetic field.
Cassini’s instruments detected the oxygen in Dione’s wake during an April 2010 flyby.
Molecular oxygen, if present on other moons as well (say, Europa or Enceladus) could potentially bond with carbon in subsurface water to form the building blocks of life. Since there’s lots of water ice on moons in the outer solar system, as well as some very powerful magnetic fields emanating from planets like Jupiter and Saturn, there’s no reason to think there isn’t more oxygen to be found… in our solar system or elsewhere.
Read the news release from the Los Alamos National Laboratory here.
Image credits: NASA/JPL/Space Science Institute. Research citation: Tokar, R. L., R. E. Johnson, M. F. Thomsen, E. C. Sittler, A. J. Coates, R. J. Wilson, F. J. Crary, D. T. Young, and G. H. Jones (2012), Detection of exospheric O2+ at Saturn’s moon Dione, Geophys. Res. Lett., 39, L03105, doi:10.1029/2011GL050452.
An Earthshine-lit moon sets over ESO's Paranal Observatory in Chile.
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It may seem like a silly question — of course there’s life on Earth — but what if we didn’t know that? What if we were looking at Earth from another vantage point, from another planet in another star system, perhaps? Would we be able to discern then if Earth were in fact teeming with life? All we’d have to go on would be the tiniest bit of light reflected off Earth, nearly lost in the intense glare of the Sun.
Researchers have found that the secret is knowing what kind of light to look for. And they discovered this with a little help from the Moon.
How Earthshine works. (ESO/L. Calçada)
By using Earthshine — sunlight light reflected off Earth onto the Moon — astronomers with the European Southern Observatory have been able to discern variations that correlate with identifying factors of our planet as being a happy home for life.
In observations made with ESO’s Very Large Telescope (VLT), the presence of oceans, clouds, atmospheric gases and even plants could be detected in the reflected Earthshine.
The breakthrough method was the use of spectropolarimetry, which measures polarized light reflected from Earth. Like polarized sunglasses are able to filter out reflected glare to allow you to see clearer, spectropolarimetry can focus on light reflected off a planet, allowing scientists to more clearly identify important biological signatures.
“The light from a distant exoplanet is overwhelmed by the glare of the host star, so it’s very difficult to analyze — a bit like trying to study a grain of dust beside a powerful light bulb,” said Stefano Bagnulo of the Armagh Observatory, Northern Ireland, and co-author of the study. “But the light reflected by a planet is polarized, while the light from the host star is not. So polarimetric techniques help us to pick out the faint reflected light of an exoplanet from the dazzling starlight.”
Since we have fairly reliable proof that life does in fact exist on Earth, this provides astronomers with a process and a benchmark for locating evidence of life on other distant worlds — life as we know it, anyway.
Main image credit: ESO/B. Tafreshi/TWAN (twanight.org). This research was presented in a paper, “Biosignatures as revealed by spectropolarimetry of Earthshine”, by M. Sterzik et al. to appear in the journal Nature on 1st March 2012. The team is composed of Michael F. Sterzik (ESO, Chile), Stefano Bagnulo (Armagh Observatory, Northern Ireland, UK) and Enric Palle (Instituto de Astrofisica de Canarias, Tenerife, Spain).
Dropping out of warp speed could have deadly results. (Image: Paramount Pictures/CBS Studios)
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Planning a little space travel to see some friends on Kepler 22b? Thinking of trying out your newly-installed FTL3000 Alcubierre Warp Drive to get you there in no time? Better not make it a surprise visit — your arrival may end up disintegrating anyone there when you show up.
“Warp” technology and faster-than-light (FTL) space travel has been a staple of science fiction for decades. The distances in space are just so vast and planetary systems — even within a single galaxy — are spaced so far apart, such a concept is needed to make casual human exploration feasible (and fit within the comforts of people’s imagination as well… nobody wants to think about Kirk and Spock bravely going to some alien planet while everyone they’ve ever known dies of old age!)
While many factors involving FTL travel are purely theoretical — and may remain in the realm of imagination for a very long time, if not ever — there are some concepts that play well with currently-accepted physics.
Warp field according to the Alcubierre drive. (AllenMcC.)
The Alcubierre warp drive is one of those concepts.
Proposed by Mexican theoretical physicist Miguel Alcubierre in 1994, the drive would propel a ship at superluminal speeds by creating a bubble of negative energy around it, expanding space (and time) behind the ship while compressing space in front of it. In much the same way that a surfer rides a wave, the bubble of space containing the ship and its passengers would be pushed at velocities not limited to the speed of light toward a destination.
Of course, when the ship reaches its destination it has to stop. And that’s when all hell breaks loose.
Researchers from the University of Sydney have done some advanced crunching of numbers regarding the effects of FTL space travel via Alcubierre drive, taking into consideration the many types of cosmic particles that would be encountered along the way. Space is not just an empty void between point A and point B… rather, it’s full of particles that have mass (as well as some that do not.) What the research team — led by Brendan McMonigal, Geraint Lewis, and Philip O’Byrne — has found is that these particles can get “swept up” into the warp bubble and focused into regions before and behind the ship, as well as within the warp bubble itself.
When the Alcubierre-driven ship decelerates from superluminal speed, the particles its bubble has gathered are released in energetic outbursts. In the case of forward-facing particles the outburst can be very energetic — enough to destroy anyone at the destination directly in front of the ship.
“Any people at the destination,” the team’s paper concludes, “would be gamma ray and high energy particle blasted into oblivion due to the extreme blueshifts for [forward] region particles.”
In other words, don’t expect much of a welcome party.
Another thing the team found is that the amount of energy released is dependent on the length of the superluminal journey, but there is potentially no limit on its intensity.
“Interestingly, the energy burst released upon arriving at the destination does not have an upper limit,” McMonigal told Universe Today in an email. “You can just keep on traveling for longer and longer distances to increase the energy that will be released as much as you like, one of the odd effects of General Relativity. Unfortunately, even for very short journeys the energy released is so large that you would completely obliterate anything in front of you.”
So how to avoid disintegrating your port of call? It may be as simple as just aiming your vessel a bit off to the side… or, it may not. The research only focused on the planar space in front of and behind the warp bubble; deadly postwarp particle beams could end up blown in all directions!
Luckily for Vulcans, Tatooinians and any acquaintances on Kepler 22b, the Alcubierre warp drive is still very much theoretical. While the mechanics work with Einstein’s General Theory of Relativity, the creation of negative energy densities is an as-of-yet unknown technology — and may be impossible.
Which could be a very good thing for us, should someone out there be planning a surprise visit our way!
Read more about Alcubierre warp drives here, and you can download the full University of Sydney team’s research paper here.
Thanks to Brendan McMonigal and Geraint Lewis for the extra information!
It may be one of the best images from Cassini yet this year! Cloud-covered Titan and tiny Prometheus (can you see it just above the rings on the right?) are literally dwarfed by their parent Saturn in an image captured on Jan. 5, 2012.
Prometheus’ pinpoint shadow can also be seen on Saturn’s cloud tops, just inside the thin, outermost F ring shadow at bottom left.
The two moons themselves couldn’t be more different; Titan, 3,200 miles (5,150 km) wide, is wrapped in a nitrogen and methane atmosphere ten times thicker than Earth’s and is covered with vast plains of dark hydrocarbon dunes and crisscrossed by rivers of liquid methane.
Prometheus imaged by Cassini in Dec. 2009.
Prometheus, on the other hand, is a potato-shaped shepherd moon 92 miles long and 53 miles wide (148 x 53 km) that orbits Saturn just inside the narrow, ropy F ring. While it doesn’t have an atmosphere, it does create some impressive effects on the icy material in the ring!
Another moon, Pandora, casts its shadow onto Saturn just outside the F ring shadow at bottom center. 50 miles (80 km) wide, Pandora shepherds the outer edge of the F ring but is itself not visible in this image. Watch an animation here.
This image was featured on the Cassini Imaging Central Laboratory for Operations (CICLOPS) website on Feb. 28, 2012. The view looks toward the southern, unilluminated side of the rings from about 1 degree below the ringplane.
Image credit: NASA / JPL / Space Science Institute.
"Forest Storm" by Ole Salomonsen (arcticlightphoto.no)
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Photographer Ole Christian Salomonsen is a master at capturing the northern lights in all their glory… as this image once again shows.
Ole describes the story behind this photo:
“Shot at the end of a ‘weak’ aurora night in Muonio, Finland. Took this at outside the cabin I was staying at close to Harriniva. The outburst came from an CME that first started disappointingly weak. I was about to go to bed but thought I should wait just a little more and see. Man am I glad I waited!!”
Man, are we glad too! Thanks for sharing these amazing views with us Ole, and keep up the great (and chilly) work!
