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!
Animation of Comet 67P/Churyumov-Gerasimenko as seen by Rosetta on June 27-28, 2014
This is really getting exciting! ESA’s Rosetta spacecraft (and the piggybacked Philae lander) are in the home stretch to arrive at Comet 67P/Churyumov-Gerasimenko in 34 days and the comet is showing up quite nicely in Rosetta’s narrow-angle camera. The animation above, assembled from 36 NAC images acquired last week, shows 67P/C-G rotating over a total elapsed time of 12.4 hours. No longer just an extra-bright pixel, it looks like a thing now!
The animation, although fascinating, only hints at the “true” shape of the comet’s nucleus. Reflected light does create a bloom effect in the imaging sensor, especially at such small resolutions, expanding the apparent size of the comet beyond its 4-by-4-pixel size. But rest assured that much, much better images are on the way as Rosetta gets closer and closer.
The spacecraft was about 86,000 km (53,440 miles) from 67P/C-G when the images were acquired. Since that time it has cut that distance in half, and by this weekend it will be less than 36,000 km (22,370 miles) from the comet. After more than a decade of traveling around the inner Solar System Rosetta is finally arriving at its goal! Click here to see where Rosetta is now.
Stay tuned for more exciting updates from Rosetta, and learn more about the mission below:
Diagram of Comet 67P/C-G compared to terrestrial landmarks (ESA)
Pretty darn big, I’d say.
The illustration above shows the relative scale of the comet that ESA’s Rosetta and Philae spacecraft will explore “up-close and personal” later this year. And while it’s one thing to say that the nucleus of Comet 67P/Churyumov-Gerasimenko is about three by five kilometers in diameter, it’s quite another to see it in context with more familiar objects. Think about it — a comet as tall as Mt Fuji!
Artist’s impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Credit: ESA–C. Carreau/ATG medialab.
At the time of this writing Rosetta is 35 days out on approach to Comet 67P/C-G, at a distance of about 51,000 km (31,700 miles) and closing. Three “big burn” maneuvers have already been performed between May 7 and June 4 to adjust the spacecraft’s course toward the incoming comet, and after smaller ones on June 18 and July 2 there are a total of five more to go. See details of Rosetta’s burn maneuvers here.
Luckily the remaining burns are relatively small compared to the first three, with the final being very brief, so any data contamination by Rosetta’s own exhaust shouldn’t become an issue once the spacecraft has established orbit in August.
Launched in March 2004, ESA’s Rosetta mission will be the first to orbit and land a probe on a comet, observing its composition and behavior as it makes its close approach to the Sun in 2015. Click here to see where Rosetta is right now.
Note: While 3-5 km seems pretty big (especially when stood on end) comet nuclei can be much larger, 10 to 20 km in diameter up to the enormous 40+ km size of Hale-Bopp. As comets go, 67P/C-G is fairly average. (Except that, come August, it will be the only comet with an Earthly spacecraft in tow!)
XCOR Aerospace's Lynx suborbital vehicle is designed to fly to 328,000 feet (Credit: XCOR)
Well, technically not space*, but suborbital, and that’d still be way cool! And what’s even cooler is that you can enter to win a trip on an XCOR Lynx Mark II suborbital flight while helping to support a good cause of your choice, courtesy of The Urgency Network’s “Ticket to Rise” campaign. Check out the dramatic spaceflight-packed promotional video and find out how to enter below:
The Urgency Network is an online platform whereby participants can win experience-based prizes by participating in campaigns that are designed to aid and support good causes, many of which assist specific communities in need, awareness groups, and conservation efforts. You earn “entries” for prize drawings by purchasing gift packages from the participating foundations or by donating time, social media presence, or money directly. It’s a way for organizations that might not have (or be able to afford) a large PR department to get funded and gain widespread exposure. Learn more about The Urgency Network here.
In the Ticket to Rise campaign, the grand prize is beyond stratospheric — literally! One lucky winner will experience a ride aboard an XCOR Lynx Mark II suborbital craft, a single-stage space vehicle that takes off from a runway to ultimately coast briefly at a maximum altitude of 328,000 feet (about 100 km), experiencing 4 minutes of microgravity before re-entry and a runway landing. It’s a supersonic 30-minute flight to the very edge of space!
(*Actually, 100 km is right at the von Karman line, so riding the Lynx Mark II past that could qualify you as an astronaut. Just sayin’.)
How a Lynx Mark II flight works (Source: XCOR)
Add to that you’d be helping any one of dozens of good causes (you can choose from different ones by clicking the “Select a Different NonProfit” text link on the donation page) and it’s a win-win for everyone. And even if you don’t get a seat aboard a spaceship (many will enter, few will win) you can still get some pretty awesome promo offers from the organizations as bulk-entry packages.
The deadline to enter the campaign is 11:59:59 p.m. EDT August 11, 2014. Drawing will be held on August 12. The Lynx flight is dependent on meeting all requirements and passing physical exams and tests by XCOR Aerospace, and although the date is expected to be in the fall of 2015, this is rocket science and things change. Read the official contest rules for all details, fine print, etc.
Artist's impression (from 2002) of Rosetta orbiting Comet 67P/Churyumov-Gerasimenko. Credit: ESA, image by AOES Medialab
It’s no surprise that there is a lot of water in comets. The “dirty snowballs” (or dusty ice-balls, more accurately) are literally filled with the stuff, so much in fact it’s thought that comets played a major role in delivering water to Earth. But every comet is unique, and the more we learn about them the more we can understand the current state of our Solar System and piece together the history of our planet.
ESA’s Rosetta spacecraft is now entering the home stretch for its rendezvous with comet 67P/Churyumov-Gerasimenko in August. While it has already visually imaged the comet on a couple of occasions since waking from its hibernation, its instruments have now successfully identified water on 67P for the first time, from a distance of 360,000 km — about the distance between Earth and the Moon.
The detection comes via Rosetta’s Microwave Instrument for Rosetta Orbiter, or MIRO, instrument. The results were distributed this past weekend to users of the IAU’s Central Bureau of Astronomical Telegrams:
S. Gulkis, Jet Propulsion Laboratory, California Institute of Technology, on behalf of the Microwave Instrument on Rosetta Orbiter (MIRO) science team, reports that the (1_10)-(1_01) water line at 556.9 GHz was first detected in Comet 67P/Churyumov-Gerasimenko with the MIRO instrument aboard the Rosetta spacecraft on June 6.55, 2014 UT. The line area is 0.39 +/-0.06 K km/s with the line amplitude of 0.48 +/-0.06 K and the line width of 0.76 +/-0.12 km/s. At the time of the observations, the spacecraft to comet distance was ~360,000 km and the heliocentric distance of the comet was 3.93 AU. An initial estimate of the water production rate based on the measurements is that it lies between 0.5 x 10^25 molecules/s and 4 x 10^25 molecules/s.
Although recent images of 67P/C-G seem to show that the comet’s brightness has decreased over the past couple of months, it is still on its way toward the Sun and with that will come more warming and undoubtedly much more activity. These recent measurements by MIRO show that the comet’s water production rate is “within the range of models being used” by scientists to anticipate its behavior.
Rosetta image of Comet 67P/C-G on June 4, 2014, from a distance of 430,000 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
This August Rosetta will become the first spacecraft to establish orbit around a comet and, in November, deploy its Philae lander onto its surface. Together these robotic explorers will observe first-hand the changes in the comet as it makes its closest approach to the Sun in August 2015. It’s going to be a very exciting year ahead, so stay tuned for more!
Giant storm clouds swirl over North Carolina (Credit: NASA / Stu Broce)
Except these are mountains made of water, not rock! Taken from an altitude of 65,000 feet, the image above shows enormous storm cells swirling high over the mountains of western North Carolina on May 23, 2014. It was captured from one of NASA’s high-altitide ER-2 aircraft during a field research flight as part of the Integrated Precipitation and Hydrology Experiment (IPHEx) campaign.
Visualization of the GPM Core Observatory satellite (NASA/Britt Griswold)
For six weeks the IPHEx campaign team from NASA, NOAA, and Duke University set up ground stations and flew ER-2 missions over the southeastern U.S., collecting data on weather and rainfall that will be used to supplement and calibrate data gathered by the GPM Core Observatory launched in February.
By the time its role in IPHEx was completed on June 16, the Lockheed ER-2 aircraft had flown more than 95 hours during 18 flights over North and South Carolina, Georgia, Florida, and Tennessee. Its high-altitude capabilities allow researchers to safely fly above storm systems, taking measurements like a satellite would.
A hot flow anomaly, or HFA, has been identified around Mercury (Credit: NASA/Duberstein)
Our Sun is constantly sending a hot stream of charged atomic particles out into space in all directions. Pouring out from holes in the Sun’s corona, this solar wind flows through the Solar System at speeds of over 400 km/s (that’s 893,000 mph). When it encounters magnetic fields, like those generated by planets, the flow of particles is deflected into a bow shock — but not necessarily in a uniform fashion. Turbulence can occur just like in air flows on Earth, and “space weather” results.
One of the more curious effects is a regional reversal of the flow of solar wind particles. Called a “hot flow anomaly,” or HFA, these energetic phenomena occur almost daily in Earth’s magnetic field, as well as on Jupiter and Saturn, and even on Mars and Venus where the magnetic fields are weak (but there are still planets blocking the stream of charged particles.)
Not to be left out in the cold, Mercury is now known to display HFAs, which have been detected for the first time by the MESSENGER spacecraft.
The first measurement was of magnetic fields that can be used to detect giant electric current sheets that lead to HFAs. The second was of the heating of the charged particles. The scientists then analyzed this information to quantify what kind of turbulence exists in the region, which provided the final smoking gun of an HFA.
“Planets have a bow shock the same way a supersonic jet does,” explains Vadim Uritsky at NASA’s Goddard Space Flight Center. “These hot flow anomalies are made of very hot solar wind deflected off the bow shock.”
Enhanced-color image of Mercury indicating the chemical and physical differences across its surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.
The solar wind is not 100% uniform; it has discontinuities within its own complex magnetic fields. When these shifting fields pile up against a planet’s bow shock they can create turbulence patterns that trap hot plasma, which in turn produces its own magnetic fields. The shockwaves, heat, and energy produced are powerful enough to actually reverse the flow of the solar wind within the HFA bulge.
And the word “hot” is putting it lightly — plasma temperatures in an HFA can reach 10 million degrees.
Mercury may be only a little larger than our Moon but it does possess an internally-generated dipolar magnetic field, unlike the Moon, Venus, and Mars which have only localized or shallow fields. The confirmed presence of HFAs on Mercury indicates that they may be a feature in all planetary bow shocks, regardless of how their magnetic fields — if any — are produced.
In related news, on June 17 MESSENGER successfully completed the first orbit adjustment maneuver to prepare it for its new — and final — low-altitude campaign, during which it will obtain its highest-resolution images ever of the planet’s surface and perform detailed investigations of its composition and magnetic field. Read more on the MESSENGER site here.
A solar prominence imaged on May 27, 2014. Earth and Moon are shown to scale at the bottom. (NASA/SDO)
Caught on camera by NASA’s Solar Dynamics Observatory, a prominence blazes hundreds of thousands of miles out from the Sun’s surface (i.e., photosphere) on May 27, 2014. The image above, seen in extreme ultraviolet wavelengths, shows a brief snapshot of the event with the column of solar plasma stretching nearly as far as the distance between Earth and the Moon.
Watch a video of the event below:
The video covers a span of about two hours.
Although it might look fiery in these images, a prominence isn’t flame — it’s powered by rising magnetic fields trapping and carrying the Sun’s superheated material up into the corona. And while this may not have been a unique or unusual event — or even particularly long-lived — it’s still an impressive reminder of the immense scale and energy of our home star!
Artist's impression of the New Horizons spacecraft. Image Credit: NASA
While many kids in the U.S. are starting their school summer vacations, New Horizons is about to get back to work! Speeding along on its way to Pluto the spacecraft has just woken up from hibernation, a nap it began five months (and 100 million miles) ago.
The next time New Horizons awakens from hibernation in December, it will be beginning its actual and long-awaited encounter with Pluto! But first the spacecraft and its team have a busy and exciting summer ahead.
New Horizons tweeted about its Father’s Day wakeup call
After an in-depth checkout of its onboard systems and instruments, the New Horizons team will “track the spacecraft to refine its orbit, do a host of instrument calibrations needed before encounter, carry out a small but important course correction, and gather some cruise science,” according to principal investigator Alan Stern in his June 11 update, aptly titled “Childhood’s End.”
What’ll be particularly exciting for us space fans is an animation of Pluto and Charon in motion around each other, to be made from new observations to be acquired in July. Because of New Horizons’ position, the view will be from a perspective not possible from Earth.
New Horizons LOng Range Reconnaissance Imager (LORRI) image of Pluto and Charon from July 2013 (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)
The next major milestone for New Horizons will be its crossing of Neptune’s orbit on August 25. (This just happens to fall on the 25th anniversary of Voyager 2’s closest approach in 1989.) “After that,” Stern says, “we’ll be in ‘Pluto space!'”
Launched on Jan. 19, 2006, New Horizons will make its closest approach to Pluto on July 14, 2015 at 11:49 UTC. Traveling nearly 35,000 mph (55,500 km/h) it’s one of the fastest vehicles ever built, moving almost 20 times faster than a bullet.
Read more from Alan Stern in his latest “PI Perspective” article on the New Horizons web site here, and check out NASA’s mission page here for the latest news as well.
“There is a lot to tell you about over the next 12 weeks, and this is just the warm-up act. Showtime — the start of the encounter — begins in just six months. This is what New Horizons was built for, and what we came to do. In a very real sense, the mission is emerging into its prime.”
– Alan Stern, New Horizons principal investigator
Also, check out a video on Pluto and the New Horizons mission here.
A "triple X" on June 10-11, 2014 with three flares from AR2087 (NASA/SDO/GSFC)
Remember yesterday when we mentioned two X-class flares erupting from the Sun within the space of about an hour? We probably should have waited a bit and gone for the trifecta: this morning the same active region flared yet again, making it three high-powered flares within a single 24-hour period.
(And to think this active region has only just come around the corner!)
On June 10, 2014, AR2087 announced its arrival around the southwestern limb of the Sun with an X2.2 flare at 11:41 UT (7:41 a.m. EDT). Then, just over an hour later, another eruption: an X1.5 flare at 12:55 UT. This got pretty much everyone’s attention… here comes 2087!
Perhaps figuring third time’s a charm, the active region blazed with a third flare this morning at 9:05 UT (5:05 a.m. EDT). “Only” an X1-class, it was the weakest of the three but AR2087 still has plenty of time for more as it makes its way around the Sun’s face — all the while aiming more and more our way, too.
Here’s a video of SDO observations showing the two June 10 flares:
X-class flares are the strongest in the letter-classification of solar flares, which send blasts of electromagnetic energy out into the Solar System. While these most recent three are low on the X-scale, they may result in increased auroral activity — especially since it appears that the first two were followed by a pair of CMEs that “cannibalized” each other on their way out. The resulting merged cloud of charged particles is expected to nick Earth’s magnetic field on Friday, June 13. (Source: Spaceweather.com)
No CME has been observed from the June 11 flare, but again: AR2087 hasn’t left the stage yet. Stay tuned!
Source: NASA. Learn more about how solar flares impact us on Earth here.
Image of the Sun as seen from Mars by Curiosity. Mercury is the circled dark spot.
NASA’s Curiosity rover may be busy exploring the rugged and rocky interior of Gale Crater, but it does get a chance to skygaze on occasion. And while looking at the Sun on June 3, 2014 (mission Sol 649) the rover’s Mastcam spotted another member of our Solar System: tiny Mercury, flitting across the Sun’s face.
Silhouetted against the bright disk of the Sun, Mercury barely appears as a hazy blur in the filtered Mastcam images. But it was moving relatively quickly during the transit, passing the darker smudges of two Earth-sized sunspots over the course of several hours.
It’s the first time Mercury has ever been imaged from Mars, and also the first time we’ve observed a planet transiting our Sun from another world besides our own.
Watch an animation of the transit below:
Animated 1-hour interval blink comparison showing Mercury’s movement across the Sun
Because the sunspots move along with the rotation of the Sun (and the Sun rotates once avery 25 days around its equator) Mercury makes a fast pass as it travels along on one of its 88-day-long years.
In reality this was no chance spotting, but rather a carefully calculated observation using the Mastcam’s right 100mm telephoto lens and neutral density filter, which is used to routinely image the Sun in order to measure the dustiness of the Martian atmosphere.
“This is a nod to the relevance of planetary transits to the history of astronomy on Earth. Observations of Venus transits were used to measure the size of the solar system, and Mercury transits were used to measure the size of the sun.”
– Mark Lemmon, Texas A&M University, member of the Mastcan science team
The next chance for Curiosity to spot Mercury will come in April 2015 and, if the rover is still operating by then — perhaps with some upgrades by future human visitors? — it may capture Earth similarly passing across the Sun in November of 2084.
