Landing on Mars in just one month!

Well, okay, it's a month and a day.  But today is Independence Day here in the U.S., and while contemplating achievements that are so far uniquely American, landing on Mars and successfully doing science there stands out in my mind.

Viking 2 image from the surface of Mars.  http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/vl2_21c056.html

The first successful landings were by Vikings 1 and 2 in 1976, our bicentennial year.  In fact, Viking 1 was originally scheduled to land on the 4th of July, until late June of that year when its orbiting mother ship snapped the first detailed photo of its intended landing site and found it was way too rough to ensure a safe landing.  A safer site was found in time to land 16 days later on an equally historic date, July 20th ("One small step...").  Over two decades later, Mars Pathfinder touched down safely on the 4th of July, 1997.

NASA has had the good fortune (along with brilliant, meticulous engineering) to succeed at 6 of 7 attempts to land on Mars.  The odd one out was Mars Polar Lander, which in 1999 apparently descended safely to a tantalizing 40 meters (130 feet) above the Martian surface before its retrorockets turned off prematurely and it free-fell to a crash landing.  Ironically, NASA has failed more frequently at Mars missions that didn't even attempt to land, including the Mariner 3 flyby mission and the planned orbiters Mariner 8, Mars Observer, and Mars Climate Orbiter.  We've enjoyed a 100% success rate in the past decade, but getting to Mars safely is still a challenge.

The Challenges of Getting to Mars: Curiosity's Seven Minutes of Terror.  Credit: NASA/JPL-Caltech

Late at night on August 5th (technically 1:30 AM EDT on August 6th), the Mars Science Laboratory mission will attempt to land the massive and highly capable Curiosity rover.  Because of Curiosity's unprecedented mass, a new landing system must be used for the first time.  The above video describes the awesome complexity of this system, which includes the planned detonation of 76 pyrotechnic charges ("fireworks").  For the rover, it will be quite a ride.  If you're here in Atlanta, you can watch the action live in the Centergy Building in Tech Square: come join our Mars Landing Party!

Gale crater, with Curiosity's landing ellipse in black and superposed approximate landing ellipse previously considered for Spirit (blue). http://photojournal.jpl.nasa.gov/catalog/PIA15687

Where will Curiosity land?  In Gale crater, a massive impact scar 150 kilometers (95 miles) across that holds a mountain of sedimentary rocks—Mount Sharp—over 5 km (3 miles) high.  The plan is to land on the flat northern crater floor and then to climb Mt. Sharp, examining each sedimentary layer as we cross it – analogous to reading a Martian history book, one page at a time.  Gale's sedimentary record is thicker than that exposed in western America's Grand Canyon, and it has been a high-priority Martian landing site for years now.  It was briefly considered as a destination for the Mars Exploration Rover Spirit, but Spirit's landing system was much less precise, and would have risked landing on the rugged crater walls or the steep slopes of Mt. Sharp.  Curiosity can instead target a small area known to be relatively safe from extensive orbital imaging, this time acquired well in advance of the planned landing date.

Happy 4th of July, and keep crossing your fingers for Curiosity.  Pending a safe landing, she will change our perceptions of Mars for years to come.

Looking for Life on Mars: Two Months Until MSL Lands!

During a time when the future of human exploration in space is uncertain, robotic explorers have taken the lead in pushing the boundaries of discovery. In just two months on August 5, 2012, the Mars Science Laboratory (MSL for short) will land on the red planet in pursuit of one of the most fundamental and important questions in science today: Is there or was there life outside of Earth? To do this, scientists and engineers have designed and built a multifaceted rover that will attack the problem with a suite of specialized instruments. This machine is no “point and shoot” camera. MSL is truly a complex autonomous laboratory capable of taking samples, processing and handling them, imaging, taking spectra, and assessing the chemistry and mineralogy of the samples it processes.

An artist’s rendering of MSL landing on Mars. http://swri.org/4org/d15/planetsci/mars.htm

One of the instruments whose primary goal it is to assess whether or not life once existed in sedimentary mounds on Mars is called SAM, which stands for Sample Analysis at Mars. SAM will search for preserved compounds that either indicate past biologic activity or are the essential precursors to life. To answer this question, SAM will first seek to understand the nature of the carbon compounds and other key elemental ingredients to life such as hydrogen, nitrogen, oxygen, phosphorus, and sulfur. These organic materials were initially deposited on both early Mars and early Earth by asteroids and comets at a rate over 1,000,000 kilograms per year. On Earth, an active biosphere reprocessed the original organics over the last four and a half billion years, but what happened to them on Mars? If life did indeed exist on Mars very early in its history, it is possible that the clues have been erased or reworked. It is also possible that SAM will discover organic compounds that have not been reworked by life, but instead by radiation and reactive surface complexes. The scientists on the SAM team certainly have their work cut out for them in piecing together this complicated puzzle.

The SAM instrument pre-launch.

http://science.gsfc.nasa.gov/sed/index.cfm?fuseAction=
projects.main&navOrgCode=699&navTab=nav_about_us

Another interesting question that SAM will be able to answer is whether or not methane is being released on the surface of Mars today. Methane is an important marker of biologic activity on Earth (think of cows) and if it was discovered to be fluctuating on Mars, it could indicate activity of living organisms. In 2003, a summer release of methane was reported to be coming from a particular region on Mars. While this observation was a tricky one to make using Earth-based telescopes, heavily questioned by the scientific community, and still yet to be confirmed by another instrument, it has the potential to have profound implications about life on Mars. SAM will be able to measure even the tiniest amount of methane and monitor its changes over time. The question of the existence and cycling of methane will be elucidated by SAM as well as other important questions about the atmosphere and climate of our planetary neighbor.  

Graphic depicting methane concentration
during the 2003 northern summer on Mars observed release of methane.

http://www.world-science.net/othernews/091209_mars-methane.htm

Geological evidence suggests that early Mars is a much different than the vast, cold, dry desert we observe today. It had an active hydrologic cycle, a protective magnetic field and thicker atmosphere. It was probably warmer and maybe even had an ocean. Also, the last few decades of astrobiological research have proven that life is capable of surviving in the most “extreme” corners of the Earth. It is still possible that life developed and thrived in this early Martian environment, and MSL will begin to probe for clues that may show us earthlings that we have company.

Image of the >3.4 billion year old Apex Chert, the first known body fossils found on Earth. Will we ever find something similar on Mars?

http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookpaleo2.html

Venus Transit

This year has been a pretty good one so far for Earth based observations, with the Super Moon and great views of the outer planets. But it's about to get even better! Depending on where you are, you'll be able to see this year's Venus transit on either June 5th or 6th. Here's some info about it.

What is a transit?
A transit occurs when a planet moves across the face of a star. In our solar system, there are only 2 planets that we can observe transiting from Earth: Mercury and Venus. But transits do occur in all planetary systems. The Kepler telescope uses the dip in light caused by a transit to find extrasolar planets.

Image courtesy of http://www.nasa.gov/vision/universe/watchtheskies/venus_transit.html

Why is it important?
There are a few reasons this Venusian transit is important:

1. This is a pretty rare opportunity. Venusian transits occur in pairs, 8 years apart. The first transit of this pair occurred in 2004. But the time between each pair of transits is really long; the last pair occurred in the late 19th century. So this is the last viewable transit for a few generations. Read more about this at the rare alignment page.
2. We don't get a lot of chances to look at Venus from Earth. It's pretty close to the sun, and so most of our telescopes either get overwhelmed by the sun or can't pick out Venus. As it's transiting, we can see some details in silhouette. 

Where can I view the Venus transit (in Atlanta)?
In North America, the transit will be visible in the evening of June 5th. That does not mean visible as in "look straight at the sun." That's never a good idea. However, there will be several observatories with solar filters on their telescopes.

• Check out a local observatory
• The Georgia Tech Observatory: Observatory opens at 6:00 PM
• Bradley Observatory at Agnes Scott College
• The Fernbank Observatory: Observatory opens at 6 PM. Planetarium will be open from 5:30-9:30 to watch west coast streaming.

Head to a meet up of local amateur astronomers

• Meet up at Grant Park: starting at 5:30 PM
• The Atlanta Astronomy Club: event at Stone Mountain, 4-8 PM, RSVP requested

Watch online

• Live Webcast from Mauna Kea Observatory

The map below shows where and when the transit will be visible- North America catches it during sunset on June 5th.

Image Courtesy of http://eclipse.gsfc.nasa.gov/OH/tran/TOV2012-Fig01.pdf

If you can't make it to an observatory, or don't live near Atlanta, there are several safe methods for observing the transit on your own. Transit of Venus has lots of information about eye safety. We hope you get a chance to see this historic transit!

Solar Eclipse this Sunday!

If you live in the western US (or Japan or China) you are in for a treat this Sunday (May 20th): there is going to be a solar eclipse! This eclipse is actually what is known as an annular eclipse due to the fact that the outer edge of the Sun will remain visible throughout the eclipse. Due to the geometry of the eclipse, some locations will observe a partial eclipse, while others will be lucky enough to see the complete annular eclipse. Sadly, those of us on the east coast will not be able to see the eclipse at all as sunset occurs before the eclipse starts. The following clip explains a lot more details about this Sunday's event:

This should make for a truly stunning sight! Do remember that even with the Moon blocking most of the Sun's disk, the remaining light it still very intense and you should *never* look directly at the Sun without proper solar viewing glasses/telescope filters. If you find yourself without proper viewing devices you can always watch a projection of the Sun during the eclipse. A few small holes in a piece of cardboard will do the trick to watch 'many eclipses' projected on the ground, as will watching the light and shadows cast through tree branches!

The following website has viewing information for all states where the eclipse will be visible before the Sun sets: http://shadowandsubstance.com/ 

Now go outside and enjoy the show this Sunday! 

Photo Credit: Dennis Mammana (1992)
Astronomy Picture of the Day: http://apod.nasa.gov/apod/ap090125.html

   

Supermoon! *Photo Update*

Source: http://photojournal.jpl.nasa.gov/catalog/PIA14011

As if you needed an excuse to look up at the night sky, this Saturday (May 5) the full moon will seem especially big and bright. It will be most striking when it’s near the horizon.


The moon is an elliptical orbit around the Earth, meaning that its distance from the Earth can vary from a minimum of 357,000 km to a maximum of 407,000 km (the average perigee and apogee are 363,300 km and 405,500 km, respectively, and the variation over the course of the year is due to the Sun's gravitational influence as the Earth and Moon move along their orbit throughout the year).


The coincidence of a full moon and the perigee (closest distance) is what dictates a Supermoon, which is what will occur on Saturday. Not only is this when the moon is at perigee, it is on the closest edge of the range of orbital perigees locations. The effect will be most noticeable when the Moon is rising/setting as objects on the horizon lend scale to the night sky.


It should be beautiful if the clouds permit :)

For more information on this Saturday’s supermoon:
http://www.accuweather.com/en/outdoor-articles/astronomy/supermoon-alert-biggest-full-m/64627 


Update: While I'm not really a photographer, my friend Brian is! Check out his great image of the Supermoon last week:

Image Source: Brian Persten :)

Giant Sunspot!

Hello again Space Enthusiasts! Just a week after the Supermoon we are witnessing another fantastic space phenomena... a giant sunspot:

Image Source: Solar Dynamics Observatory HMI Intesitygram

http://sdo.gsfc.nasa.gov/data/

For scale, this magnetically active region is larger than the Earth! On May 10th this active region released an intense M-Class solar flare. There did not appear to be any large Coronal Mass Ejection (CME) associated with this flare, however only a day later a CME did occur that is now en route to the Earth. This bundle of energetic plasma is due to arrive at Earth's magnetosphere on May 14th, and may result in enhanced geomagnetic activity.

So you may be wondering just how frequently sunspots occur, and whether this large sunspot is unique. The answer is that the Sun is a highly dynamic object, and goes through a cycle of magnetic activity that lasts approximately 11 years and is associated with the magnetic field of the Sun reversing direction. During this cycle the Sun goes from a pretty quiescent disk to one with sunspots increasing in frequency, size, and intensity. We've been telescopically observing and cataloguing sunspots since the early 1600s, and have found a beautifully repeating pattern:

Image Source: http://www.globalwarmingart.com/wiki/File:Sunspot_Numbers_png   

We are currently ramping up to solar maximum (in 2012-2013), and therefore should see an increase in the number of sunspots and the amount of solar activity like flares, and CMEs. When the packet of energetic plasma and magnetic field that make up a CME reaches the Earth it can have a wide range of effects from generating beautifully intense aurora to damaging space borne assets to disrupting GPS and communication systems. In only the most extreme cases can the resulting geomagnetic storm (which is the general term used to describe a perturbation to the Earth's magnetosphere during a CME encounter) cause damage to electric power grids and oil pipelines, and cause redirection of cross-polar flights.

To get a realtime look at the Sun, check out the websites of the Solar Dynamics Observatory (SDO), STEREO, and the SOlar and Heliospheric Observatory (SOHO). At these sites you can view the Sun in the visible light emission (like the image above), and also see what the Sun looks like in the UltraViolet or UV part of the spectrum (in false color of course since we can't see at those wavelengths). You can also get Space Weather updates, alerts, and other great news at www.SpaceWeather.com!

The Sun in the EUV (9.4 nm) and FUV (170 nm).

Image Source: http://sdo.gsfc.nasa.gov/data/

One last riddle to leave you with: When is a sunspot not a sunspot?

Answer: 

When it's a Venus Transit!!! Coming on June 5th! 

A post on this exciting event is coming soon!

Fly me to a moon... or two... or three!

The European Space Agency (ESA) has chosen its next major mission: it's headed to Jupiter to check out three of the planet's largest moons. The JUICE mission, which stands for JUpiter ICy moon Explorer, is expected to launch in 2022 and arrive at the Jupiter system in 2030.

Source: http://www.esa.int/esaCP/SEM9I4QWJ1H_index_0.html

The ESA's selection of the JUICE mission is an exciting decision that affects planetary scientists around the world. It will provide a path for exploration of the outer solar system that will extend well beyond the current Cassini, Juno and New Horizons missions, which will all conclude within the next six years. In selecting this mission, the ESA sends a message to the scientific community that exploration of the outer solar system is an important priority.

Once JUICE arrives in the Jovian system in 2030, it will perform several flyby encounters of Callisto and Europa, and finally transfer to a suite of orbits about Ganymede. This mission is the first orbiter of an icy moon and provides the opportunity to study the potential for habitability of worlds around gas giant planets.

Source: http://photojournal.jpl.nasa.gov/catalog/PIA09352

Ganymede is definitely my favorite, as I spent most of my graduate career studying this exciting moon. It is the largest moon in the solar system.  It has a liquid water ocean beneath its icy surface. It also has aurora and is the only moon we know of that has its own magnetic field. This mission specifically seeks to characterize the extent of the subsurface ocean and its relationship to the interior structure of this fascinating moon. It will also examine the composition, distribution and evolution of surface features, and, through in situ measurements, will aid in our understanding of Ganymede's the near-space environment.

Ganymede is not the only object to be studied by this mission, the spacecraft will also spend time studying Jupiter as an archetype for a gas giant (of which we now have hundreds of exoplanet examples!). It will study Jupiter's atmosphere and magnetosphere and the coupled interactions of Jupiter and its family of icy moons. The mission also plans to execute several flyby encounters of Europa and Callisto, which will allow us to take a closer look at these beautifully diverse examples of icy worlds. Callisto is one of the oldest surfaces and represents a history of the early Jovian system. Its interior structure is a mystery, and we're excited to get better images and measurements to learn more about how this body formed and what it can tell us about the earliest 'recorded' period in the solar system. Europa has a subsurface ocean that is likely in direct contact with silicates and has demonstrated recent activity. The induced currents and magnetic fields generated in its ocean give us direct clues as to its depth and composition (compositions, along with features/structures on the surface, can tell us how active it is and where materials are sourced from).

All in all it is a very exciting time to be a planetary scientist, and I look forward to seeing this mission develop over the next decade in preparation for launch!

Source: http://photojournal.jpl.nasa.gov/catalog/PIA04532

Story reposted from my GT release: http://amplifier.gatech.edu/articles/2012/05/next-stop-jupiter