Solar System Archives

May 27, 2014December 23, 2015 by David Dickinson

Seeing in Triplicate: Catching a Rare Triple Shadow Transit of Jupiter’s Moons

Hubble nabs a triple shadow transit in this false color image taken in 2004. Credit: NASA/HST.

The planet Jupiter is always fascinating to watch. Not only do surface features pop in and out of existence on its swirling cloud tops, but its super fast rotation — once every 9.9 hours — assures its face changes rapidly. And the motion of its four large Galilean moons is captivating to observe as well. Next week offers a special treat for well-placed observers: a triple shadow transit of the moons Callisto, Europa and Ganymede on the evening of June 3rd.

The view at 19:00 UT/3:00 PM EDT on June 3rd. Credit: Starry Night Education Software.

Now for the bad news: only a small slice of the planet will witness this rare treat in dusk skies. This is because Jupiter starts the month of June 40 degrees east of the Sun and currently sets around 11 PM local, just 3 hours after local sunset. Never fear, though, it may just be possible to spy a portion of this triple transit from North American longitudes with a little careful planning.

The action begins on June 3^rd at 15:20 Universal Time as Callisto’s shadow slides on to the disk of Jupiter, to be followed by Europa and Ganymede’s shadow in quick succession hours later. All three shadows are cast back onto the disk of Jupiter from 18:05 to 19:53 UT, favoring European and African longitudes at sunset. The final shadow, that of Ganymede, moves off the disk of Jupiter at 21:31 UT.

The hemisphere of the Earth facing towards Jupiter from the beginning of the triple shadow transit to the end. the red line marks the day/night terminator. Credit: Stellarium.

The following video simulation begins at around 15:00 UT just prior to the ingress of Callisto’s shadow and runs through 22:00 UT:

Triple shadow transits of Jupiter’s moons are fairly rare: the last such event occurred last year on October 12^th, 2013 favoring North America and the next won’t occur until January 24^th, 2015. Jean Meeus calculated that only 31 such events involving 3 different Jovian moons either transiting Jupiter and/or casting shadows onto its disk occur as seen from Earth between 1981 and 2040. The June 3^rd event is also the longest in the same 60 year period studied.

The 1:2:4 orbital resonance of the Jovian moons Io, Europa and Ganymede. Credit: Wikimedia Commons.

Can four shadow transits occur at once? Unfortunately, the answer is no. The inner three moons are in a 1:2:4 resonance, meaning that one will always be left out of the picture when two are in front. This also means that Callisto must be included for any triple shadow transit to occur. Next week’s event sees Callisto, Europa and Ganymede crossing in front of Jupiter and casting shadows onto its disk while Io is hidden behind Jupiter in its enormous shadow. Callisto is also the only one of the four large Jovian moons that can “miss” the disk of Jupiter on certain years, owing to the slight inclination of its orbit to the ecliptic. Callisto thus doesn’t always cast a shadow onto the disk of Jupiter, and we’re currently in the middle of a cycle of Callisto shadow transits that started in July of 2013 and runs through July 2016. These “Callisto transit seasons” occur twice during Jupiter’s 11.8 year orbit, and triple shadow transits must also occur within these periods.

So, what’s a North American observer to do? Well, it is possible to spot and track Jupiter with a telescope in the broad daylight. Jupiter rises at around 9:20 AM local in early June, and the waxing crescent Moon passes 5.4 degrees south of it on June 1^st. The Moon stands 30 degrees from the planet on June 3^rd, and it may be juuusst possible to use it as a guide to the daytime event. A “GoTo” telescope with precise pointing will make this task even easier, allowing you to track Jupiter and the triple shadow transit across the daytime sky from North American longitudes. But be sure to physically block the blazing June Sun behind a building or structure to avoid accidentally catching its blinding glare in the eyepiece!

The orientation of Jupiter the Moon and the Sun at 4PM EDT on June 3rd. Credit: Stellarium. — The orientation of Jupiter, the Moon and the Sun at 4PM EDT on June 3rd. Credit: Stellarium.

Do the shadows of the moons look slightly different to you? A triple shadow transit is a great time to compare them to one another, from the inky hard black dot of the inner moons Europa and Io, to the diffuse large shadow of Callisto. With practice, you can actually identify which moon is casting a shadow during any transit just by its size and appearance!

A study of three multi-shadow transits: last year's (upper left) a double shadow transit from early 2014 (upper right) and 2004 (bottom. Photos by author. — A study of three multi-shadow transits: last year’s (upper left) a double shadow transit from early 2014 (upper right) and 2004 (bottom). Photos by author.

Shadow transits of Jupiter’s moons also played an interesting role in the history of astronomy as well. Danish astronomer Ole Rømer noted that shadow transits were being observed at slightly different times than predicted depending on the distance of Jupiter and the Earth, and made the first rough calculation of the speed of light in 1676 based on this remarkable insight. Celestial navigators were also intrigued for centuries with the idea of using the phenomena of Jupiter’s moons as a natural clock to gauge longitude. It’s a sound idea in theory, though in practice, it proved tough to make accurate observations from the pitching deck of a ship at sea.

Jupiter captured near the daytime Moon. Photo by author.

Miss the June 3^rd event? There’s still two fine opportunities to see Jupiter do its impression of the Earth-Moon system and appear to have only one satellite – Callisto – on the evenings of May 30^th and June 7^th.

From there, Jupiter slides lower into the dusk as June progresses and heads towards solar conjunction on July 24^th.

Let us know if you manage to catch sight of this rare event!

-Send those shadow transit pics in to Universe Today at our Flickr forum.

May 24, 2014December 23, 2015 by Ken Kremer

Opportunity Overlooks Ridge for Spectacular Vista of Vast Martian Crater and Habitable Zone Ahead

NASA’s Opportunity Mars rover captures sweeping panoramic vista near the ridgeline of 22 km (14 mi) wide Endeavour Crater’s western rim. The center is southeastward and also clearly shows the distant rim. See the complete panorama below. This navcam panorama was stitched from images taken on May 10, 2014 (Sol 3659) and colorized. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com
More mosaics and 10 year route map below[/caption]

NASA’s incredibly long lived Opportunity rover has driven to the ridgeline of a Martian mountain and captured spectacular panoramic vistas peering down into the vast expanse of huge Endeavour crater and out along the jagged rim segments leading to her next target – which scientists believe holds minerals indicative of a habitable zone. See mosaic views above and below.

Since departing the world famous ‘Jelly Doughnut’ rock by the summit of ‘Solander Point’ in February, Opportunity has spent the past several months driving south and exploring intriguing rock outcrops on ‘Murray Ridge’ located along the eroded western rim of Endeavour Crater.

The renowned robot is now exploring a region of outcrops atop the rims ridge that’s a possible site harboring deposits of hydrated clay minerals, formed in the ancient past when Mars was warmer and wetter.

The ten year old Red Planet rover first reached the rim of Endeavour Crater in August 2011. She has captured numerous sweeping gorgeous vistas during her first of its kind expedition on the surface of another planet by an alien probe from Earth.

Read my earlier story detailing the top 10 discoveries from twin sisters Spirit and Opportunity according to Deputy Principal Investigator Prof. Ray Arvidson – here.

The gigantic crater spans 14 miles (22 kilometers) in diameter.

So there is endless enthralling terrain to investigate – for at least another 10 years!

The floor of Endeavour crater is filled with dark sand, brighter dust, and, in the distance, dusty haze, says NASA.

This vista of the Endeavour Crater rim was acquired by NASA's Mars Exploration Rover Opportunity's panoramic camera on April 18, 2014, from the southern end of "Murray Ridge" on the western rim of the crater. In mid-May, the rover approached the dark outcrops on the flank of the hill at right. The high peak in the distance on the right is informally named "Cape Tribulation" and is about 1.2 miles (2 kilometers) to the south of Opportunity's position when this view was recorded Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ. — This vista of the Endeavour Crater rim was acquired by NASA’s Mars Exploration Rover Opportunity’s panoramic camera on April 18, 2014, from the southern end of “Murray Ridge” on the western rim of the crater. In mid-May, the rover approached the dark outcrops on the flank of the hill at right. The high peak in the distance on the right is informally named “Cape Tribulation” and is about 1.2 miles (2 kilometers) to the south of Opportunity’s position when this view was recorded Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

Opportunity’s goal all the while has been to doggedly trek southwards towards exposures of aluminum-rich clays detected from orbit by NASA’s powerful Martian ‘Spysat’ – the Mars Reconnaissance Orbiter (MRO) – while gathering context data at rock outcrops at Murray Ridge along the winding way.

These aluminum-rich clay minerals, or phyllosilicates, likely formed billions of years ago in flowing liquid neutral water which is more conducive to life, compared to more acidic environments explored earlier in the mission, and is therefore potentially indicative of a Martian habitable zone and a scientific goldmine.

The science and engineering team has used the high resolution MRO spectral and imaging data to more efficiently direct Opportunity southwards along the Endeavour crater rim and towards the biggest caches of the clay minerals – which were detected at a mountainous rim segment called ‘Cape Tribulation’ and which is seen in the panoramic vistas.

Although Cape Tribulation still lies some 1.2 miles (2 kilometers) further south, the rover has just arrived at a region which the team believes shows the first signatures of the clay minerals.

“The rover is exploring the region of aluminum-hydroxyl clay minerals seen from orbit,” said NASA in a mission update.

The six wheeled robot will utilize her mast mounted cameras and arm mounted microscopic imager (MI) and APXS spectrometer to gather images and measurements to unlock the mysteries of Mars ability to support life – past or present.

“The more we explore Mars, the more interesting it becomes. These latest findings present yet another kind of gift that just happens to coincide with Opportunity’s 10th anniversary on Mars,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program.

“We’re finding more places where Mars reveals a warmer and wetter planet in its history. This gives us greater incentive to continue seeking evidence of past life on Mars.”

Opportunity Mars rover peers over mountain ridge for gorgeous vista into floor and out to distant rim of 22 km (14 mi) wide Endeavour Crater. This pancam camera view was assembled from images taken on May 16, 2014 (Sol 3665) with false color sky. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com

And Opportunity is now power-rich following a series of fortuitous wind cleaning events that substantially cleared the dust off the power generating solar wing arrays.

The solar array energy production has reached 761 watt-hours compared to about 900 watt-hours at landing in 2004 and only about 270 watt-hours just before Christmastime in December 2013.

“Solar panels [are] cleanest since about sol 1600 [September 2008],” says mission science team member Larry Crumpler.

More power means more work time and more bonus science studies and data return.

So the robot survived magnificently through her 6th harsh Martian winter with plenty of science rich targets planned ahead during the southern hemisphere Martian spring and summer.

Opportunity by Solander Point peak – 2nd Mars Decade Starts here! NASA’s Opportunity rover captured this panoramic mosaic on Dec. 10, 2013 (Sol 3512) near the summit of “Solander Point” on the western rim of Endeavour Crater where she starts Decade 2 on the Red Planet. She is currently investigating outcrops of potential clay minerals formed in liquid water on her 1st mountain climbing adventure. Assembled from Sol 3512 navcam raw images. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com — Opportunity by Solander Point peak – 2nd Mars Decade Starts here!
NASA’s Opportunity rover captured this panoramic mosaic on Dec. 10, 2013 (Sol 3512) near the summit of “Solander Point” on the western rim of Endeavour Crater where she starts Decade 2 on the Red Planet. She is currently investigating outcrops of potential clay minerals formed in liquid water on her 1st mountain climbing adventure. Assembled from Sol 3512 navcam raw images. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com

Today, May 24, marks Opportunity’s 3673nd Sol or Martian Day roving Mars – compared to a warranty of just 90 Sols.

So far she has snapped over 192,600 amazing images on the first overland expedition across the Red Planet.

Her total odometry stands at over 24.49 miles (39.41 kilometers) since touchdown on Jan. 24, 2004 at Meridiani Planum.

Meanwhile on the opposite side of Mars, Opportunity’s younger sister rover Curiosity is trekking towards gigantic Mount Sharp and just drilled into her 3rd Red Planet rock at Kimberley.

Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, MAVEN, MOM, Mars and more planetary and human spaceflight news.

Ken Kremer

Traverse Map for NASA’s Opportunity rover from 2004 to 2014 - A Decade on Mars. This map shows the entire path the rover has driven during a decade on Mars and over 3660 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location along Murray Ridge south of Solander Point summit at the western rim of Endeavour Crater and heading to clay minerals at Cape Tribulation. Opportunity discovered clay minerals at Esperance - indicative of a habitable zone. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer — Traverse Map for NASA’s Opportunity rover from 2004 to 2014 – A Decade on Mars
This map shows the entire path the rover has driven during a decade on Mars and over 3660 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location along Murray Ridge south of Solander Point summit at the western rim of Endeavour Crater and heading to clay minerals at Cape Tribulation. Opportunity discovered clay minerals at Esperance – indicative of a habitable zone. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer

May 21, 2014December 23, 2015 by Ken Kremer

Curiosity says ‘Goodbye Kimberley’ after Parting Laser Blasts and Seeking New Adventures Ahead

The Mars Hand Lens Imager on NASA's Curiosity Mars rover provided this nighttime view of a hole produced by the rover's drill and, inside the hole, a line of scars produced by the rover's rock-zapping laser. The hole is 0.63 inch (1.6 centimeters) in diameter. The camera used its own white-light LEDs to illuminate the scene on May 13, 2014. Credit: NASA/JPL-Caltech/MSSS

NASA’s rover Curiosity said ‘Goodbye Kimberley’ having fulfilled her objectives of drilling into a cold red sandstone slab, sampling the tantalizing grey colored interior and pelting the fresh bore hole with a pinpoint series of parting laser blasts before seeking new adventures on the road ahead towards the inviting slopes of Mount Sharp, her ultimate destination.

Curiosity successfully drilled her 3rd hole deep into the ‘Windjama’ rock target at the base of Mount Remarkable and within the science waypoint at a region called “The Kimberley” on May 5, Sol 621.

Since then, the 1 ton robot carefully scrutinized the resulting 2.6 inches (6.5 centimeters) deep bore hole and the mound of dark grey colored drill tailings piled around for an up close examination of the texture and composition with the MAHLI camera and spectrometers at the end of her 7-foot-long (2 meters) arm to glean every last drop of science before moving on.

Curiosity’s panoramic view departing Mount Remarkable and ‘The Kimberley Waypoint’ where rover conducted 3rd drilling campaign inside Gale Crater on Mars. The navcam raw images were taken on Sol 630, May 15, 2014, stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer – kenkremer.com/Marco Di Lorenzo

Multiple scars clearly visible inside the drill hole and on the Martian surface resulting from the million watt laser firings of the Mast mounted Chemistry and Camera (ChemCam) instrument left no doubt of Curiosity’s capabilities or intentions.

Furthermore she successfully delivered pulverized and sieved samples to the pair of onboard miniaturized chemistry labs; the Chemistry and Mineralogy instrument (CheMin) and the Sample Analysis at Mars instrument (SAM) – for chemical and compositional analysis.

Curiosity completed an “intensive investigation of ‘The Kimberley’, having successfully drilled, acquired and dropped samples into CheMin and SAM,” wrote science team member Ken Herkenhoff in an update.

“MAHLI has taken lots of excellent images of the drill hole, including some during the night with LEDs on, nicely showing the ChemCam LIBS spots.”

“The initial analysis of this new sample by Chemin is ongoing, requiring repeated overnight integration to build up high-quality data,” says Herkenhoff.

The rover’s earth bound handlers also decided that one drill campaign into Kimberley was enough.

So the rover will not be drilling into any other rock targets here.

Composite photo mosaic shows deployment of NASA Curiosity rovers robotic arm and two holes after drilling into ‘Windjana’ sandstone rock on May 5, 2014, Sol 621, at Mount Remarkable as missions third drill target for sample analysis by rover’s chemistry labs. The navcam raw images were stitched together from several Martian days up to Sol 621, May 5, 2014 and colorized. Credit: NASA/JPL-Caltech/Ken Kremer - kenkremer.com/Marco Di Lorenzo — Composite photo mosaic shows deployment of NASA Curiosity rovers robotic arm and two holes after drilling into ‘Windjana’ sandstone rock on May 5, 2014, Sol 621, at Mount Remarkable as missions third drill target for sample analysis by rover’s chemistry labs. The navcam raw images were stitched together from several Martian days up to Sol 621, May 5, 2014 and colorized. Credit: NASA/JPL-Caltech/Ken Kremer – kenkremer.com/Marco Di Lorenzo

And it may be a very long time before the next drilling since the guiding team of scientists and engineers wants desperately to get on and arrive at the foothills of Mount Sharp as soon as possible.

But the robot will undoubtedly be busy with further analysis of the ‘Windjana’ sample along the way, since there’s plenty of leftover sample material stored in the CHIMRA sample processing mechanism to allow future delivery of samples when the rover periodically pauses during driving.

This May 12, 2014, view from the Mars Hand Lens Imager (MAHLI) in NASA's Curiosity Mars Rover shows the rock target "Windjana" and its immediate surroundings after inspection of the site by the rover by drilling and other activities. Credit: NASA/JPL-Caltech/MSSS — This May 12, 2014, view from the Mars Hand Lens Imager (MAHLI) in NASA’s Curiosity Mars Rover shows the rock target “Windjana” and its immediate surroundings after inspection of the site by the rover by drilling and other activities. Credit: NASA/JPL-Caltech/MSSS

“Windjana” is named after a gorge in Western Australia.

It’s been a full year since the first two drill campaigns were conducted during 2013 at the ‘John Klein’ and ‘Cumberland’ outcrop targets inside Yellowknife Bay. They were both mudstone rock outcrops and the interiors were markedly different in color.

“The drill tailings from this rock are darker-toned and less red than we saw at the two previous drill sites,” said Jim Bell of Arizona State University, Tempe, deputy principal investigator for Curiosity’s Mast Camera (Mastcam).

“This suggests that the detailed chemical and mineral analysis that will be coming from Curiosity’s other instruments could reveal different materials than we’ve seen before. We can’t wait to find out!”

The science team chose Windjana for drilling “to analyze the cementing material that holds together sand-size grains in this sandstone,” says NASA.

Curiosity’s Panoramic view of Mount Remarkable at ‘The Kimberley Waypoint’ where rover conducted 3rd drilling campaign inside Gale Crater on Mars. The navcam raw images were taken on Sol 603, April 17, 2014, stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer – kenkremer.com/Marco Di Lorenzo. Featured on APOD - Astronomy Picture of the Day on May 7, 2014 — Curiosity’s Panoramic view of Mount Remarkable at ‘The Kimberley Waypoint’ where rover conducted 3rd drilling campaign inside Gale Crater on Mars. The navcam raw images were taken on Sol 603, April 17, 2014, stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer – kenkremer.com/Marco Di Lorenzo
Featured on APOD – Astronomy Picture of the Day on May 7, 2014

“The Kimberley Waypoint was selected because it has interesting, complex stratigraphy,” Curiosity Principal Investigator John Grotzinger, of the California Institute of Technology, Pasadena, told me.

Curiosity departed the ancient lakebed at the Yellowknife Bay region in July 2013 where she discovered a habitable zone with the key chemical elements and a chemical energy source that could have supported microbial life billions of years ago – and thereby accomplished the primary goal of the mission.

Windjama lies some 2.5 miles (4 kilometers) southwest of Yellowknife Bay.

Curiosity still has about another 4 kilometers to go to reach the foothills of Mount Sharp sometime later this year.

The sedimentary layers of Mount Sharp, which reaches 3.4 miles (5.5 km) into the Martian sky, is the six wheeled robots ultimate destination inside Gale Crater because it holds caches of water altered minerals. Such minerals could possibly indicate locations that sustained potential Martian life forms, past or present, if they ever existed.

Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, LADEE, MAVEN, MOM, Mars and more planetary and human spaceflight news.

Ken Kremer

May 21, 2014December 23, 2015 by Bob King

Potential Weekend Meteor Shower Will Pelt the Moon Too!

the shaded or speckled area indicates where May Camelopardalids can stoke the lunar surface. telescopic observers will want to point their telescopes to the shaded dark area at the top right of the lunar disk.

If the hoped-for meteor blast materializes this Friday night / Saturday morning (May 23-24) Earth won’t be the only world getting peppered with debris strewn by comet 209P/LINEAR. The moon will zoom through the comet’s dusty filaments in tandem with us.

Bill Cooke, lead for NASA’s Meteoroid Environment Office, alerts skywatchers to the possibility of lunar meteorite impacts starting around 9:30 p.m. CDT Friday night through 6 a.m. CDT (2:30-11 UTC) Saturday morning with a peak around 1-3 a.m. CDT (6-8 UTC).

While western hemisphere observers will be in the best location, these times indicate that European and African skywatchers might also get a taste of the action around the start of the lunar shower. And while South America is too far south for viewing the Earth-directed Camelopardalids, the moon will be in a good position to have a go at lunar meteor hunting. Find your moonrise time HERE.

Earlier lunar impact on the earthlit portion of the moon. Credit: NASA — Earlier lunar impact on the earthlit portion of the moon recorded by video camera. Credit: NASA

The thick crescent moon will be well-placed around peak viewing time for East Coast skywatchers, shining above Venus in the eastern sky near the start of morning twilight. For the Midwest, the moon will just be rising at that hour, while skywatchers living in the western half of the country will have to wait until after maximum for a look:

“Anyone in the U.S. should monitor the moon until dawn,” said Cooke, who estimates that impacts might shine briefly at magnitude +8-9.

Any meteors hitting the moon will also be burning up as meteors in Earth's skies from the direction of the dim constellation Camelopardalis the Giraffe located in the northern sky below Polaris in the Little Dipper. Stellarium — Any meteors hitting the moon will also be burning up as meteors in Earth’s skies from the direction of the dim constellation Camelopardalis the Giraffe located in the northern sky below Polaris in the Little Dipper. Stellarium

“The models indicate the Camelopardalids have some big particles but move slowly around 16 ‘clicks’ a second (16 km/sec or 10 miles per second). It all depends on kinetic energy”, he added. Kinetic energy is the energy an object possesses due to its motion. Even small objects can pack a wallop if they’re moving swiftly.

Bright lunar meteorite impact recorded on video on September 11, 2013. The estimated 900-lb. space rock flared to 4th magnitude.

Lunar crescents are ideal for meteor impact monitoring because much of the moon is in shadow, illuminated only by the dim glow of earthlight. Any meteor strikes stand out as tiny flashes against the darkened moonscape. For casual watching of lunar meteor impacts, you’ll need a 4-inch or larger telescope magnifying from 40x up to around 100x. Higher magnification is unnecessary as it restricts the field of view.

I can’t say how easy it will be to catch one, but it will require patience and a sort of casual vigilance. In other words, don’t look too hard. Try to relax your eyes while taking in the view. That’s why the favored method for capturing lunar impacts is a video camera hooked up to a telescope set to automatically track the moon. That way you can examine your results later in the light of day. Seeing a meteor hit live would truly be the experience of a lifetime. Here are some additional helpful tips.

Meteorite impact flashes seen from 2005 to the present. Fewer are seen in the white areas (lunar highlands) because flashes blend in compared to those occurring on the darker lunar 'seas' or maria. Credit: NASA — Meteorite impact flashes seen from 2005 to the present. Fewer are recorded in the white areas (lunar highlands) because the flashes blend into the landscape compared to those occurring on the darker lunar ‘seas’ or maria. Click for more information on lunar impacts. Credit: NASA

On average, about 73,000 lbs. (33 metric tons) of meteoroid material strike Earth’s atmosphere every day with only tiny fraction of it falling to the ground as meteorites. But the moon has virtually no atmosphere. With nothing in the way, even small pebbles strike its surface with great energy. It’s estimated that a 10-lb. (5 kg) meteoroid can excavate a crater 30 feet (9 meters) across and hurl 165,000 lbs. of lunar soil across the surface.

A meteoroid that size on an Earth-bound trajectory would not only be slowed down by the atmosphere but the pressure and heat it experienced during the plunge would ablate it into very small, safe pieces.

NASA astronomers are just as excited as you and I are about the potential new meteor shower. If you plan to take pictures or video of meteors streaking through Earth’s skies or get lucky enough to see one striking the moon, please send your observations / photos / videos to Brooke Boen ([email protected]) at NASA’s Marshall Space Flight Center. Scientists there will use the data to better understand and characterize this newly born meteor blast.

On the night of May 23-24, Bill Cooke will host a live web chat from 11 p.m. to 3 a.m. EDT with a view of the skies over Huntsville, Alabama. Check it out.

May 20, 2014December 23, 2015 by Bob King

How to See 209P/LINEAR, the Comet Brewing Up Saturday’s Surprise Meteor Shower

Comet 209P/LINEAR may still be faint but it's a beautiful object in this time exposure by Austrian astrophotographer Michael Jaeger. The stars appear as trails because the photographer followed the comet during the exposure.

As we anxiously await the arrival of a potentially rich new meteor shower this weekend, its parent comet, 209P/LINEAR, draws ever closer and brighter. Today it shines feebly at around magnitude +13.7 yet possesses a classic form with bright head and tail. It’s rapidly approaching Earth, picking up speed every night and hopefully will be bright enough to see in your telescope very soon.

As it approaches Earth in the coming nights, comet 209P/LINEAR will appear to move quickly across the sky, traveling from Leo Minor to southern Hydra in little over a week. All maps created with Chris Marriott's SkyMap software — As it approaches Earth in the coming nights, comet 209P/LINEAR will move quickly across the sky, traveling from Ursa Major to southern Hydra in just 10 days. When closest on May 28-29, the comet will cover 10 degrees per day or just shy of 1/2 degree per hour. All maps created with Chris Marriott’s SkyMap software

The comet was discovered in Feb. 2004 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) automated sky survey. Given its stellar appearance at the time of discovery it was first thought to be an asteroid, but photos taken the following month photos by Rob McNaught (Siding Spring Observatory, Australia) revealed a narrow tail. Unlike long period comets Hale-Bopp and the late Comet ISON that swing around the sun once every few thousand years or few million years, this one’s a frequent visitor, dropping by every 5.09 years.

This detailed map shows the comet's path from Leo Minor across the backside of the Sickle of Leo May 23-26. Hopefully it will be bright enough then to spot in an 8-inch or larger telescope. Click to enlarge and then print out for use at the telescope. — This detailed map shows the comet’s path from Leo Minor across the backside of the Sickle of Leo May 23-26. Hopefully it will be bright enough then to spot in an 8-inch or larger telescope. On May 25, it passes close to the colorful double star Gamma Leonis and a pair of NGC galaxies. Stars plotted to magnitude +9. Click to enlarge and then print out for use at the telescope.

209P/LINEAR belongs to the Jupiter family of comets, a group of comets with periods of less than 20 years whose orbits are controlled by Jupiter. When closest at perihelion, 209P/LINEAR coasts some 90 million miles from the sun; the far end of its orbit crosses that of Jupiter. Comets that ply the gravitational domain of the solar system’s largest planet occasionally get their orbits realigned. In 2012, during a relatively close pass of that planet, Jupiter perturbed 209P’s orbit, bringing the comet and its debris trails to within 280,000 miles (450,000 km) of Earth’s orbit, close enough to spark the meteor shower predicted for this Friday night/Saturday morning May 23-24.

Track of the comet through from May 27-29 through the dim constellation Sextans south of Leo. — Track of the comet from May 27-29 through Sextans to the Hydra-Crater border with positions shown every 3 hours. Times are CDT. Click to enlarge.

This time around the sun, the comet itself will fly just 5.15 million miles (21 times the distance to the moon) from Earth around 3 a.m. CDT (8 hours UT) May 29 a little more than 3 weeks after perihelion, making it the 9th closest comet encounter ever observed. Given , you’d think 209P would become a bright object, perhaps even visible with the naked eye, but predictions call for it to reach about magnitude +11 at best. That means you’ll need an 8-inch telescope and dark sky to see it well. Either the comet’s very small or producing dust at a declining rate or both. Research published by Quanzhi Ye and Paul A. Wiegert describes the comet’s current dust production as low, a sign that 209P could be transitioning to a dormant comet or asteroid.

Light curve for comet 209P/LINEAR predicts a maximum magnitude of around 11. Click for more information. Credit: Seiichi Yoshida — Light curve for comet 209P/LINEAR forecasts a maximum magnitude of around 11. Dates are shown along the bottom and magnitude scale along the side. Click for additional information. Credit: Seiichi Yoshida

Fortunately, the moon’s out of the way this week and next when 209P/LINEAR is closest and brightest. Since we enjoy comets in part because of their unpredictability, maybe a few surprises will be in the offing including a brighter than expected appearance. The maps will help you track down 209P during the best part of its apparition. I deliberately chose ‘black stars on a white background’ for clarity in use at the telescope. It also saves on printer ink!

A brand new meteor shower shooting 100 and potentially as many as 400 meteors an hour may radiate from the dim constellation Camelopardalis below the North Star Saturday morning May 24. Each is crumb or pebble of debris lost by 209P/LINEAR during earlier cycles around the sun. This map shows the sky facing north around 2 a.m. from the Saturday May 24 from the central U.S. Stellarium

We’re grateful for the dust 209P/LINEAR carelessly lost during its many passes in the 19th and early 20th centuries. Earth is expected to pass through multiple filaments of debris overnight Friday May 23-24 with the peak of at least 100 meteors per hour – about as good as a typical Perseid or Geminid shower – occurring around 2 a.m. CDT (7 hours UT).

If it’s cloudy or you’re not in the sweet zone for viewing either the comet or the potential shower, astrophysicist Gianluca Masi will offer a live feed of the comet at the Virtual Telescope Project website scheduled to begin at 3 p.m. CDT (8 p.m. Greenwich Time) May 22. A second meteor shower live feed will start at 12:30 a.m. CDT (5:30 a.m. Greenwich Time) Friday night/Saturday morning May 23-24.

SLOOH will also cover 209P/LINEAR live on the Web with telescopes on the Canary Islands starting at 5 p.m. CDT (6 p.m. EDT, 4 p.m. MDT and 3 p.m. PDT) May 23. Live meteor shower coverage featuring astronomer Bob Berman of Astronomy Magazine begins at 10 p.m. CDT. Viewers can ask questions by using hashtag #slooh.

A very exciting weekend lies ahead!

May 20, 2014December 23, 2015 by Elizabeth Howell

NASA Mars Lander InSight ‘Go’ For Construction

Artist's conception of the NASA InSight Mars lander. Credit: NASA/JPL-Caltech

It’s time to get ready for Mars, again! NASA has given the approval to begin construction on its 2016 mission, the Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport (InSight) mission.

As the mission implies, the lander (which isn’t moveable) will focus on learning more about the inside of Mars. The idea is to figure out how terrestrial planets are “differentiated” inside between core, mantle and crust. Also, watchers of the Mars program may recognize some parts of the lander, as it will borrow the design from the successful Phoenix mission in 2008.

“We will incorporate many features from our Phoenix spacecraft into InSight, but the differences between the missions require some differences in the InSight spacecraft,” stated Stu Spath, InSight program manager at Lockheed Martin.

“For example, the InSight mission duration is 630 days longer than Phoenix, which means the lander will have to endure a wider range of environmental conditions on the surface.”

View of Mars' surface near the north pole from the Phoenix lander. Credit: NASA/JPL-Calech/University of Arizona — View of Mars’ surface near the north pole from the Phoenix lander. Credit: NASA/JPL-Calech/University of Arizona

NASA mission planners are still determining where InSight will go, but they expect it will be a site near the equator of Mars and that it will last at least two years on the surface.

The Mars lander will include a robotic arm with “surface and burrowing” instruments whose projects are led by the French and German space agencies, which are CNES (National Center of Space Studies) and DLR (German Center for Aerospace), respectively. CNES will contribute a seismic experiment to look at “Marsquakes” and when meteors smack the surface, while DLR’s science experiment will look at interior planetary heat.

Mars on March 8, 2014 shows not only clouds over Hellas but evening limb clouds. Credit: W.L. Chin

The seismometer will sit on the surface, covered up to protect it from the cold and wind, while the heat-flow probe will be hammered in about three to five yards or meters. Investigators also plan an experiment that will communicate with NASA’s Deep Space Network antenna network to see how much the rotation of Mars wobbles, which could hint if the core of the Red Planet is solid or liquid. The mission will also include wind, temperature and pressure sensors, as well as a magnetometer.

“Mars actually offers an advantage over Earth itself for understanding how habitable planetary surfaces can form,” stated Bruce Banerdt, InSight principal investigator at NASA’s Jet Propulsion Laboratory. “Both planets underwent the same early processes. But Mars, being smaller, cooled faster and became less active while Earth kept churning. So Mars better preserves the evidence about the early stages of rocky planets’ development.”

Construction will be led by Lockheed Martin. You can check out more information about InSight at this website. NASA has several missions working at Mars right now, such as the Mars Curiosity rover, the Opportunity rover and the orbiting Mars Reconnaissance Orbiter and Mars Odyssey spacecraft.

Source: Jet Propulsion Laboratory

May 19, 2014December 23, 2015 by Elizabeth Howell

Saturn Aurora Sparkles In New Hubble Images

Several images of an aurora on Saturn's north pole taken in April and May 2013 by the Hubble Space Telescope. Credit: NASA/ESA, Acknowledgement: J. Nichols (University of Leicester)

It’s amazing to see what some flashes of light can tell us. New images the Hubble Space Telescope took of Saturn not only reveal auroras dancing in the north pole, but also reveal some interesting things about the giant planet’s magnetic field.

“It appears that when particles from the Sun hit Saturn, the magnetotail collapses and later reconfigures itself, an event that is reflected in the dynamics of its auroras,” the European Space Agency wrote in a description of the image.

“Saturn was caught during a very dynamic light show – some of the bursts of light seen shooting around Saturn’s polar regions traveled more than three times faster than the speed of the gas giant’s roughly 10-hour rotation period.”

And for those readers that remember the music video from Saturn that the Cassini spacecraft took — also of auroras — ESA said this new research complements what the other spacecraft did, too.

The research has been accepted for publication in Geophysical Research Letters.

Source: ESA

May 16, 2014December 23, 2015 by Elizabeth Howell

Venus Express Prepares to Descend into Hell

Artist's impression of the surface of Venus. Credit: ESA/AOES

Venus is definitely not a friendly planet for humanity. Soviet landers that arrived on the surface a few decades back were crushed pretty quickly. Its surface temperature is more than 842 degrees Fahrenheit (450 degrees Celsius) and the atmosphere is full of noxious gases.

But descending into this pressure-filled cooker is exactly what Venus Express is going to do shortly. The European Space Agency spacecraft will conclude eight years of orbital operations with an attempt to fall into the planet. The maneuvers are complicated, and there’s no guarantee they will go as planned, but ESA plans to make the plunge by the end of this year.

For the better part of a decade, Venus Express has been orbiting the planet every 24 hours, swinging in an elliptical orbit that ranges from 155 miles (250 kilometers ) to 41,010 miles (66,000 kilometers). But now the spacecraft is almost out of fuel, and will now be redirected for “experimental aerobreaking” to slow down through skimming the atmosphere.

The maneuvers will take place between June 18 and July 17, where controllers hope to gain some information about the planet’s magnetic field, solar wind, temperature and pressure.

“The campaign also provides the opportunity to develop and practice the critical operations techniques required for aerobraking, an experience that will be precious for the preparation of future planetary missions that may require it operationally,” stated Paolo Ferri, head of mission operations.

No one is sure if the spacecraft will run out of fuel, or even if it survives, but if it does its orbit could be raised to do a few more scientific observations of the planet before going into the atmosphere forever.

Venus’ Express scientific treasure trove includes measuring hydrogen atom escape in the atmosphere, checking out the planet’s clouds and tracking the slowing rotation of the planet (which is happening for reasons that are not quite clear.) It also discovered an ozone layer on the planet.

Source: European Space Agency

May 15, 2014December 23, 2015 by Elizabeth Howell

It’s Alive! Rosetta’s Comet Flares As It Approaches The Sun

A close-up of comet 67P/Churyumov–Gerasimenko taken from 1.24 million miles (2 million km) away. The image was obtained by the Rosetta spacecraft in April 2014 as it approached the comet for a close-up view. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Wow! This image shows the target comet for the Rosetta mission starting to develop a tail. This bodes well for the European Space Agency spacecraft, which is on its way to study Comet 67P/Churyumov–Gerasimenko later this year to learn more about the origins of the solar system.

“It’s beginning to look like a real comet,” stated Holger Sierks, principal investigator for OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System.)

“It’s hard to believe that only a few months from now, Rosetta will be deep inside this cloud of dust and en route to the origin of the comet’s activity,” added Sierks, who is with the Max Planck Institute for Solar System Research in Germany.

The picture was one of a series taken over six weeks, between March 27 and May 4, as the spacecraft zoomed to within 1.24 million miles (two million kilometers) of the target. You can see the full animation by clicking on the image below.

Comet 67P/Churyumov–Gerasimenko develops a coma in this sequence of pictures taken by Rosetta, a European Space Agency spacecraft. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA — Comet 67P/Churyumov–Gerasimenko develops a coma in this sequence of pictures taken by Rosetta (click the picture to see the animation), a European Space Agency spacecraft. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The comet is now about four times as far from the Sun as the Earth is. Even from afar, the Sun’s heat is warming the comet’s ice, causing dust and vapor to carry out into space — forming the coma. The coma will develop into a long tail when the comet gets even closer to the sun.

Rosetta will be the comet’s companion as it draws closer to the sun; its closest approach will be in August 2015, when it is between the orbits of Earth and Mars. So far, the spacecraft’s 11 instruments appear to be in excellent health, ESA stated, although the agency is remaining cautious as the rendezvous date approaches. The spacecraft will begin orbital insertion activities later this month, and send out its Philae lander in November.

“We have a challenging three months ahead of us as we navigate closer to the comet, but after a 10-year journey it’s great to be able to say that our spacecraft is ready to conduct unique science at comet 67P/C-G,” stated Fred Jansen, ESA’s Rosetta mission manager.

Source: European Space Agency

May 15, 2014December 23, 2015 by Elizabeth Howell

Earth’s Lightning Ramps Up With The Solar Wind: Study

Time-lapse photo of several lightning strikes at night. Credit: NOAA Photo Library, NOAA Central Library; OAR/ERL/National Severe Storms Laboratory (NSSL)

As the northern hemisphere enters the hazy days of summer, thunderstorms will freckle many of our nights and days. What causes these sudden bursts of light that flash through the sky? Previous research showed that one cause is cosmic rays from space, generated by supernovas. But a new paper shows that something much closer and powerful is also responsible: solar wind from our own Sun.

First, a quick primer on what the solar wind is. It’s a continuous stream of particles from the Sun, and it tends to pick up when the Sun emits solar flares. These flares are more frequent when sunspots are in greater numbers on the star’s surface, which happens when the Sun’s magnetic activity increases. The Sun’s activity falls and rises on an 11-year cycle, and 2014 happens to be close to the peak of one of those cycles.

“Our main result,” said lead author Chris Scott (of the University of Reading) in a statement, “is that we have found evidence that high-speed solar wind streams can increase lightning rates. This may be an actual increase in lightning or an increase in the magnitude of lightning, lifting it above the detection threshold of measurement instruments.”

The researchers discovered “a substantial and significant increase in lightning rates” for up to 40 days after solar winds hit Earth’s atmosphere. The reasons behind this are still poorly understood, but the researchers say this could be because the air’s electrical charge changes as the particles (which are themselves electrically charged) hit the atmosphere.

If this is proven, this could give a new nuance to weather forecasters who could incorporate information about solar wind streams that are being watched by spacecraft. This stream of particles would change with the sun’s 27-day rotation, and researchers hope this could improve long-range forecasts.

The study is based on UK Met Office lightning strike data in the United Kingdom between 2000 and 2005, more specifically anything that happened within 500 kilometers (310 miles) of central England. They also used data from NASA’s Advanced Composition Explorer (ACE), a spacecraft that examines the solar wind.

After each event, the researchers uncovered an average of 422 lightning strikes in the United Kingdom in the next 40 days, compared to an average of 321 lightning strikes in between these events. (The peak was about 12 to 18 days after an event.)

Artist's impression of the solar wind from the sun (left) interacting with Earth's magnetosphere (right). Credit: NASA — Artist’s impression of the solar wind from the sun (left) interacting with Earth’s magnetosphere (right). Credit: NASA

The researchers pointed out that the magnetic field of Earth does deflect many of these particles, but in the cases observed the particles would have been energetic enough to move into “cloud-forming regions” of the Earth’s atmosphere.

“We propose that these particles, while not having sufficient energies to reach the ground and be detected there, nevertheless electrify the atmosphere as they collide with it, altering the electrical properties of the air and thus influencing the rate or intensity at which lightning occurs,” Scott stated.

You can read more about the paper in Environmental Research Letters.

Source: IOP Publishing