Saturday, June 25, 2011

'Magnetic Ropes' on the Sun Cause Solar Storms

I always enjoy hearing about new discoveries in space science. I especially enjoy it when we learn more about our Sun. AND I really really enjoy it when it's a discovery made by researchers from my old University and have met in the past.

On the left, NASA's Solar Dynamics Observatory shows the magnetic rope as the thick looped structure extending above the edge of the sun. On the right, SDO observes as the surrounding cool magnetic field lines are pushed away by the intruding magnetic rope seen on the left. Both images are taken almost simultaneously (within three seconds of each other). [Credit: NASA and GMU]

George Mason University professor Jie Zhang and his graduate student Xin Cheng proved the existence of 'magnetic ropes' that cause solar storms. They used images from NASA Solar Dynamic Observatory (SDO) to solve this blank in the understanding of heliophysics (the physics of the Sun). They presented their findings

Here are press articles from GMU and that describe a bit about the discovery. Essentially, there is now an understanding of what causes solar storms, a twisting tangle of magnetic fields that can create an immense eruption. Though it was already believed that these ropes could lead to eruptions, this research confirms it.

With this now known, astronomers are a step closer to understanding and predicting solar storms. This will be of a great benefit to just about anyone who relies on electricity. Solar storms have the potential to knock out power grids for extended periods (perhaps years) and cause catastrophic damage.

This sort of solar research is essential for protecting infrastructure and communication around the globe. So, I am thankful for the intelligent work of these researchers and hopefully much more will come. The results of the study were reported at the American Astronomical Society Solar Physics Division Meeting, which is being held from June 12 to 16 at New Mexico State University in Las Cruces.

[You may have noticed I haven't been as active lately. I've been a bit busy planning my 4th of July break, of which I'll likely be gone for a week. I'm looking at leaving for North Carolina's Outer Banks on the 30th. I'll probably make a couple scheduled posts. I have also been filling out job apps like it's my job. Seriously, there has to be a better way than filling in all the same info over and over again on every different website's application form. Oh well, it has gotta get done. Also, I am going to a friends wedding this weekend, so see you all on Monday. Hope you get to enjoy some sun and pleasant weather.]

Wednesday, June 22, 2011

Becoming An Ice Hunter

Just last week, I was praising and encouraging people to participate with the ambitious citizen scientist project, the Zooniverse. Now, if looking for exoplanets, identifying galaxies, examining the surface of the Moon, watching for solar storms, and studying the structure of our Milky Way Galaxy all sound boring to you (and really it shouldn't), then be prepared for their latest project: Ice Hunters.

Ice Hunters will have members of the public contribute in modern space exploration unlike any other way before. You can examine images from the giant Magellan and Subaru telescopes looking for Kuiper Belt Objects, or KBOs. These Pluto-like objects are lumps of ice, frozen chunks that exist on the fringes of our Solar System and may take millennia to circle the Sun once. Astronomers have already identified over a thousand KBOs, and there are likely tens of thousands left to be discovered.

Now, if discovering new objects in our own Solar System wasn't cool enough, you will help choose the next destination or two for a spacecraft to visit. The New Horizons probe is set to buzz past Pluto in July 2015, giving us an unprecedented view of the ice dwarf. Astronomers and researchers are on the edge of their seats for this encounter and are expecting to be amazed. But after New Horizons sails past Pluto, it is going to keep heading deeper into the outer solar system, deep into the Kuiper Belt, the territory of KBOs.

New Horizons has been given the capability to explore further objects than Pluto, and will be visiting one or two of them. With Ice Hunters, the KBOs found by the public will be considered as possible targets. KBOs have never been seen up close before, so your discovery may be one of the first of these objects ever studied up close and personal. Your discovery could lead to a bunch of new understanding about how our Solar System works, and maybe even an indication of how water was brought to the Earth.

It's an exciting prospect, especially for members of the general public. The site makes it just as easy as the other Zooniverse projects. Humans turn out to be really good at identifying these objects, were as computers tend to get confused by false positives in the data. You can read more about how it works here. That is why they need you. They need your eyes and your intelligence, there is far more data available than their are researchers.

Check out Ice Hunters and New Horizons maybe visiting your discovery soon!

Tuesday, June 21, 2011

Astro-Lesson: Summer Solstice

The Sun as it appeared just a few minutes before today's solstice occurred. (Credit: NASA/SDO)

As of 17:16 UTC (1:16 p.m. Eastern US time) today, June 21, 2001, the Sun will reach the furthest north of its travel across the sky. This event is known as the summer solstice in the north, and consequently has the most daylight of the year. In the southern hemisphere, it would be the winter solstice and the shortest day.

The summer solstice is generally used to either mark the beginning of summer or the midpoint, neither is really right or wrong. Seasons are kind of an abstract notion as it is. But from this point on, the remaining days of the year will get slightly shorter until we reach the winter solstice on December 22.  But, that doesn't necessarily mean cooler days, as anyone who has experienced the month of August knows. (And again, for all of those in the southern hemisphere, just the opposite is true.)

Solstice and Equinox. (Credit: NASA)

What causes this change in seasons has everything to do with the tilt of the Earth. The distance of the Earth from the Sun has nothing to do with it, though I know many people who have been incorrectly taught so or envision it this way because the Earth's orbit is slightly oval. In fact, for the northern hemisphere, summer occurs when the Earth is furthest away from the Sun. And if distance were the cause, then both hemispheres would have the seasons at the same time.

What really happens is that the Earth appears to "wobble" around the Sun on its tilted axis. And because one hemisphere is pointed tilted more towards the Sun due to this wobble, it gets more direct sunlight and longer days. This happens until the Sun reaches a certain number of degrees (currently 23° 26′ 16″) north or south of the equator, and then the Sun appears to travel back across the sky to the next point. These lines at north and south are known as the Tropic of Cancer and Tropic of Capricorn, respectfully. And tracing the Sun's path between these two points, every day at the same time, leads to the formation of a figure-8 pattern called an analemma.
Solar Analemma over Athens, Greece. The lowest point is on the winter solstice, the highest is the summer, the crossings are the spring and fall equinoxes. (Source)

Anyways, I hope you have enjoyed the longest day of the year hear in the northern hemisphere. It tends to be a well celebrated day all around the world, and has been since ancient times. Sites like Stonehenge and the ruins of ancient cultures, like the Greeks and Mayans and Egyptians, all have indications of marking the importance of the summer solstice. It's an astronomical event!

Monday, June 20, 2011

So Much Science, So Little Time

I hope everyone enjoyed their Father's Day weekend, I know I had some good times with my family. There has been some great astronomy stuff happening (as always) so I figured I'll dump some links.

This hemispheric view of Venus was created using more than a decade of radar investigations culminating in the 1990-1994 Magellan mission, and is centered on the planet's North Pole. This composite image was processed to improve contrast and to emphasize small features, and was color-coded to represent elevation. Image Credit: NASA/JPL/USGS

First up, Life's Little Mysteries is presenting The Greatest Mysteries of the Cosmos every Friday this summer. They are starting with our solar systems and first was The Greatest Mysteries of Venus. It is a great opener to understanding out planetary evil twin.

Dawn captured this view of Vesta on June 14, 2011. Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA

NASA's Dawn spacecraft is getting closer and closer to asteroid Vesta by the day. It now has a better resolution than the Hubble Space Telescope. The image above was taken on June 14, 2011 from a distance of about 265,000 kilometers. Each pixel spans roughly 25 kilometers. As The Planetary Society explains it:
There's clearly a deep crater in the northern part of the image. And the outline is definitely lumpier than the outlines of similarly sized bodies in the outer solar system (like Mimas and Enceladus), but we knew that already; the rock that Vesta is made of is able to hold up steeper mountains than the relatively low-strength ices that outer planet moons are made of. Apart from that, it's still hard to tell what's albedo differences and what's topography. But that won't be true for long.

In the skies of Mars, there was recently an amazing alignment. On June 1, Mars' tiny moon Phobos slipped in front of Jupiter from the view point of the ESA’s Mars Express orbiter. Above is an animation of the event, using photos taken with the Mars Express’ High Resolution Stereo Camera (HRSC). In addition to being a cool event, the observation also helps to improve knowledge of the martian moon's orbital position.

Color composite of Helene from June 18, 2011 flyby. There’s a bit of a blur because the moon shifted position in the frames slightly between images. NASA / JPL / SSI / J. Major

And speaking of tiny moons, the Cassini spacecraft out at Saturn performed a flyby of Helene on June 18. The second-closest flyby of the icy little moon helped to map the surface and better understand the history and gully-like features seen on previous flybys. You can read more about it here.

In other news, the Space Shuttle Atlantis had its final payload delivered on Saturday, June 18. The shuttle is on track for the final flight, STS-135, on July 8. The main payload is the Italian- built “Raffaello” logistics module for the International Space Station, which contains 5 tons of "critical space parts, crew supplies and experiments to sustain space station operations once the shuttles are retired". The secondary payload is dubbed the Robotic Refueling Mission (RRM) – a sort of “gas station in space”.

And finally, tomorrow, June 21, is the longest day of the year for the northern hemisphere, the summer solstice. Hopefully everyone enjoys their long and warm day. Though consequently, it is the shortest day in the southern hemisphere, so keep warm guys.