Philae is awake… and taking pictures! This image, acquired last night with the lander’s CIVA (Comet nucleus Infrared and Visible Analyzer) instrument, shows the left and right solar panels of ESA’s well-traveled Rosetta spacecraft, upon which the 100-kilogram Philae is mounted.
Philae successfully emerged from hibernation on March 28 via a wake-up call from ESA.
After over a decade of traveling across the inner Solar System, Rosetta and Philae are now in the home stretch of their ultimate mission: to orbit and achieve a soft landing on comet 67/P Churyumov-Gerasimenko. It will be the first time either feat has ever been attempted by a spacecraft. Read more here.
Comet ISON’s gone but positively not forgotten. The National Science Foundation today shared the results of their Comet ISON Photography Contest. You’ll recognize many of the names because so many of their photos have graced stories written for Universe Today.
Come take a look back at the high points of one of the most highly anticipated and studied comets of all time. Click each photo for a full-sized view. Congratulations to all the winners!
We’ve got a hot comet on our hands. Comet Jacques barely cracked magnitude +11 at the time of its March 13 discovery, but just three weeks later, amateur astronomers have already spotted it in large binoculars at magnitude +9.5. Expert comet observer Michael Mattiazzo, who maintains the Southern Comets Homepage,predicts that if Comet Jacques continues its rapid rise in brightness, it might become faintly visible with the naked eye by July.
The comet’s currently inching across the southern constellation Antlia headed toward Puppis and Monoceros later this month. Observers describe it as “very diffuse” with a large, dim coma and moderately compact core. Photos show a short tail pointing east-northeast. This past weekend C/2014 E2 passed closest to the Earth at 89.3 million miles (144 million km) on its way to perihelion on July 2.
Right now, observers in southern latitudes have the viewing advantage. As seen from South America and Australia, Comet Jacques floats high in the southwestern sky at nightfall. Observers in mid-northern latitudes can see it too, but have to set their sights lower. A week ago I tried tracking down this newcomer with a 37-cm (15-inch) Dobsonian reflector around 9 o’clock. With Jacques only 14 degrees high at the time I had to kneel beside the telescope to see into the eyepiece. Try as I might, I suspected only a fuzzy patch at best. Light pollution and low altitude were partly to blame, but Jacques’ diffuse appearance may have contributed to the uncertain observation. Other mid-northern latitude observers may have shared my sore kneecap experience in similar attempts.
But that will soon change. C/2014 E2 continues to increase in altitude throughout the month, offering easier viewing as soon as mid-month. April 16 through early May the moon will be gone from the sky and provide a needed dark time slot for viewing the comet before it’s lost in evening twilight. Comet Jacques will likely be brighter than magnitude 9 as it slides from Puppis into Monoceros.
Find a place with a dark sky to the southwest and start looking at the end of evening twilight when the comet is highest. The map shows stars in reverse making it easier to use in crowded star fields.
By mid-July, Comet Jacques will have passed perihelion 61 million miles (98 million km) from the sun and transition into the morning sky as it rapidly swings northward across Taurus, Auriga and Perseus. Though the comet will be half again as far from Earth as it is today, it’s expected to become considerably brighter and more condensed after a good “roasting” by the sun.
Hang onto your space helmets. With a few moves of the mouse, you can now follow the European Rosetta mission to its target comet with this interactive 3-D simulator. Go ahead and give it a click – it’s live! The new simulator was created by INOVE Space Models, the same group that gave us the 3-D solar system and Comet ISON interactive models.
The embedded version gives you a taste, so be sure to also check out the full-screen version. You can either click play to watch the mission from start to finish or you can drop it at key points by selecting from list of 11 highlights on the left side of your screen. A tick-tock at the bottom of the screen helps reference the time and what the spacecraft is doing at that moment in the video.
To interact with the model, simply click the screen. The action stops, allowing you to zoom in and out by scrolling; to change orbital viewpoints hold down the mouse button and drag. So easy!
I like the realism of the simulation, the attention paid to the planets’ variable spin rates and orbital periods and how well model illustrates the complicated maneuvers required to “fling” the probe to Comet Churyumov-Gerasimenko. And I do mean fling. Watching the video from a face-on solar system perspective I was struck by how Rosetta’s flight path resembled a spiral after repeated gravity assists by Mars and Earth.
Whether you’re a teacher or an armchair space enthusiast looking for an easy-to-understand, graphic way to find out how Rosetta will meet its target, I doubt you’ll find a more effective tool.
Little Philae is awake! ESA sent a wake-up call to the 100-kg (220-lb) lander riding aboard the Rosetta spacecraft this morning at 06:00 GMT, bringing it out of its nearly 33-month-long slumber and beginning its preparation for its upcoming (and historic) landing on the surface of a comet in November.
Unlike Rosetta, which awoke in January via a pre-programmed signal, Philae received a “personal wake-up call” from Earth, 655 million kilometers away.
A confirmation signal from the lander was received by ESA five and a half hours later at 11:35 GMT.
After over a decade of traveling across the inner Solar System, Rosetta and Philae are now in the home stretch of their ultimate mission: to orbit and achieve a soft landing on the inbound comet 67/P Churyumov-Gerasimenko. It will be the first time either feat has ever been attempted — and hopefully achieved — by a spacecraft.
After Rosetta maneuvers to meet up with the comet in May and actually enters orbit around it in August, it will search its surface for a good place for Philae to make its landing in November.
With a robotic investigator both on and around it, 67/P CG will reveal to us in intimate detail what a comet is made of and really happens to it as it makes its close approach to the Sun.
“Landing on the surface is the cherry on the icing on the cake for the Rosetta mission on top of all the great science that will be done by the orbiter in 2014 and 2015. A good chunk of this year will be spent identifying where we will land, but also taking vital measurements of the comet before it becomes highly active. No one has ever attempted this before and we are very excited about the challenge!”
– Matt Taylor, Rosetta project scientist
Meanwhile, today’s successful wake-up call let the Rosetta team know Philae is doing well. Further systems checks are planned for the lander throughout April.
Watch an animation of the deployment and landing of Philae on comet 67/P CG below:
Comet Siding Spring, on its way to a close brush with Mars on October 19, has been kicking up a storm lately. New images from Hubble Space Telescope taken on March 11, when the comet was just this side of Jupiter, reveal multiple jets of gas and dust.
Discovered in January 2013 by Robert H. McNaught at Siding Spring Observatory in Australia, the comet is falling toward the sun along a roughly 1 million year orbit. It will gradually brighten through spring and summer until reaching binocular brightness this fall when it passes 130 million miles (209 million km) from Earth.
Astronomers were particularly interested in getting images when Earth crossed the comet’s orbital plane, the path the comet takes as it orbits the sun. The positioning of the two bodies allowed Hubble to make crucial observations of how fast dust particles streamed off the nucleus.
“This is critical information that we need to determine whether, and to what degree, dust grains in the coma of the comet will impact Mars and spacecraft in the vicinity of Mars,” said Jian-Yang Li of the Planetary Science Institute in Tucson, Arizona.
On October 19 this year, Comet Siding Spring will pass within 84,000 miles (135,000 km) of Mars or less than half the distance of our moon. There’s a distinct possibility that orbiting Mars probes like NASA’s Mars Reconnaissance Orbiter and the European Mars Expressmight be enveloped by the comet’s coma (hazy atmosphere) and pelted by dust.
While comet dust particles are only 1 to 1/10,000 of a centimeter wide, they’ll be moving at 124,000 mph (200,000 km/hr). At that speed even dust motes small can be destructive. Plans are being considered to alter the orbits of the spacecraft to evade the worst of the potential blast. On the bright side, the Red Planet may witness a spectacular meteor storm! Protected by the atmosphere, the Martian rovers aren’t expected to be affected.
I know where I’ll be on October 19 – in the front yard peering at Mars through my telescope. Even if the comet doesn’t affect the planet, seeing the two overlap in conjunction will be a sight not to miss.
As Rosetta limbers up for its close-up encounter with a comet, we have visual confirmation that it’s on the right track! The comet spied its destination — Comet 67P/Churymov-Gerasimenko — using its OSIRIS wide-angle camera and narrow-angle camera on March 20 and March 21.
“Finally seeing our target after a 10 year journey through space is an incredible feeling,” stated OSIRIS principal investigator Holger Sierks from the Max Planck Institute for Solar System Research in Germany. “These first images taken from such a huge distance show us that OSIRIS is ready for the upcoming adventure.”
The image comes as Rosetta is preparing its science instruments for its encounter in August.
“Currently, Rosetta is on a trajectory that would, if unchanged, take it past the comet at a distance of approximately 50 000 km and at a relative speed of 800 m/s. A critical series of manoeuvres beginning in May will gradually reduce Rosetta’s velocity relative to the comet to just 1 m/s and bring it to within 100 km by the first week of August,” the European Space Agency stated.
Here’s an animation of how big the comet will appear to Rosetta as it gets closer:
“Between May and August the 4 km-wide comet will gradually ‘grow’ in Rosetta’s field of view from appearing to have a diameter of less than one camera pixel to well over 2000 pixels – equivalent to a resolution of around 2 m per pixel – allowing the first surface features to be resolved.”
For more information on the science commissioning, check out the Rosetta blog.
Welcome to the first day of spring! If you have a clear night between now and April 1, celebrate the new season with a pilgrimage to the countryside to ponder the eerie glow of the zodiacal light. Look for a large, diffuse, tapering cone of light poking up from the western horizon between 90 minutes and two hours after sunset. While the zodiacal light appears only as bright as the Milky Way, you’re actually looking at the second brightest object in the night sky. No kidding. If you could crunch it all into a little ball, it would shine at magnitude -8.5, far brighter than Venus and bested only by the full moon.
Sunlight reflecting off countless dust particles shed by comets and spawned by asteroid collisions creates the luminous cone of light. First time observers might think they’re looking at skyglow from light pollution but the tapering shape and distinctive tilt mark this glow as interplanetary dust.
Like the planets, the dust resides in the plane of the solar system. In spring, that plane (called the ecliptic) tilts steeply up from the western horizon after sunset, “lifting” the chubby thumb of light high enough to clear the horizon haze and stand out against a dark sky for northern hemisphere observers. In October and November the ecliptic is once again tilted upright, but this time before dawn. While the zodiacal light is present year-round, it’s usually tipped at a shallow angle and camouflaged by horizon haze. No so for skywatchers in tropical and equatorial latitudes. There the ecliptic is tilted steeply all year long, and the light can be seen anytime there’s no moon in the sky.
Now through April 1 and again from April 17-30 are the best nights for viewing because the moon will be absent from the sky. The cone is widest near the western horizon and narrows as you direct your gaze upward and to the left. At its apex, where it touches the V-shape Hyades star cluster, it continues into the even fainter zodiacal band and gegenschein, but more about that in a moment. Sweep your gaze in broad strokes back and forth across the western sky to help you discern the Z-light’s distinctive conical shape. And be sure to look for something HUGE. This thing is a monster – indeed, one of the largest entities in the solar system.
Observers fortunate enough to live under or with access truly dark skies can trace the zodiacal light all the way across the sky as the zodiacal band.
Midway along its length, 180 degrees opposite the sun, a slightly brighter circular patch called the gegenschein (German for ‘counter glow’) embedded in the band.
Dust particles there get an extra brightness boost because they face the sun square on, much like the moon does when full. While I usually see only a section of the zodiacal band from my dark observing site, the gegenschein is often visible as a diffuse, hazy patch of light about 6 degree across a little brighter than the sky background.
Dutch astronomer H. C. van de Hulst determined that the dust particles responsible for the zodiacal light and its cousins the zodiacal band and gegenschein are about 0.04 inch (1 mm) in diameter and separated, on average, by about 5 miles (8 km).
The particles form a low density, lens-shaped cloud of dust that’s thickest within the plane of the solar system but in reality covers the entire sky but ever so thinly. Sunlight absorbed by the particles is re-emitted as invisible infrared (heat) radiation. This re-radiation robs the dust of energy, causing the particles to spiral slowly into the sun. Fresh dust from the vaporization of cometary ices as well as collisions of asteroids replenishes the cloud.
According to a study by Joseph Hahn and colleagues of the Clementine Mission data, comet dust accounts for the majority of the zodiacal dust within 1 a.u. (93 million miles) of the sun; a mix of asteroidal and comet dust makes up the remainder.
Stepping out on a spring evening to look at the zodiacal light, we can appreciate how small things can come together to create something grand.
Get those binoculars ready: an icy interloper from the Oort cloud is about to grace the night sky.
The comet is C/2012 K1 PanSTARRS, and it’s currently just passed from the constellation Hercules into Corona Borealis and presents a good target for observers high in the sky in the hours before dawn. In fact, from our Tampa based latitude, K1 PanSTARRS is nearly at the zenith at around 6 AM local.
Observers currently place K1 PanSTARRS at magnitude +10.5 and brightening and showing a small condensed coma. Through the eyepiece, a comet at this stage will often resemble a fuzzy, unresolved globular star cluster.
And the good news is, K1 PanSTARRS will continue to brighten, headed northward through the early morning and then into the evening sky before reaching solar conjunction on August 9th, when it’ll actually pass behind the Sun for a few hours as seen from from our vantage point. We actually get two good apparitions of Comet K1 PanSTARRS: one for the northern hemisphere in the Spring and one for the southern hemisphere after it reaches perihelion and crosses south of the ecliptic plane in August.
And it’ll be worth keeping an eye out for K1 PanSTARRS online as well, as it passes into the view of SOHO’s LASCO C3 camera on August 2 before exiting its 15 degree field of view on August 16th.
This actually means the comet will reach opposition twice from our Earthbound vantage point: once on April 15th, and again on November 7th. And, as is often the case, this comet arrives six months early –or late, depending how you look at it- to be a fine naked eye object. Had K1 PanSTARRS reached perihelion in January, we’d have really been in for a show, with the comet only around 0.05 Astronomical Units (about 7.7 million kilometers) from the Earth!
But alas, such was not to be. At its best, K1 PanSTARRS will be hidden by the glare of the Sun at its very best, to emerge into the southern sky. The comet has a steeply inclined 142 degree retrograde orbit, and thus approaches the inner solar system from high above the ecliptic plane.
These coming last weeks of March are a great time to search out K1 PanSTARRS as the Moon reaches Last Quarter this weekend and heads towards New on March 30th, beginning a two week “moonless period for AM observing in early April. Projections by veteran comet observer Seiichi Yoshida suggest that K1 PanSTARRS will begin to brighten dramatically towards +8th magnitude through April. We first picked up the now posthumous comet ISON with binoculars around this magnitude last Fall. Keep in mind, like nebula and galaxies, the apparent brightness of a comet is spread out over its surface area. This can make a +10th magnitude comet much tougher to spot than a pinpoint +10 magnitude star.
We actually prefer our trusty Canon 15x45IS image stabilized binoculars for comet hunting… they’re powerful and easy to deploy on a cold March morning!
Here’s a handy list of notable events to watch for as Comet C/2012 K1 PanSTARRS crosses the springtime sky. Only passages of less than one degree near stars greater than magnitude +6 are mentioned except where otherwise noted:
March 17th: Comet C/2012 K1 PanSTARRS passes into the constellation Corona Borealis.
March 21st: Passes the +5.8 magnitude star Upsilon Coronae Borealis.
March 29th: Passes the +5.4 magnitude star Rho Coronae Borealis.
March 30th: The Moon reaches New phase.
April 2nd: Passes the +4.8 magnitude star Kappa Coronae Borealis.
April 7th: Passes the +5.2 magnitude star Mu Coronae Borealis.
April 10th: Passes into the constellation of Boötes.
April 10th: Passes the +5 magnitude wide binary pair Nu Boötis.
April 15th: Comet K1 PanSTARRS reaches opposition, rising opposite to the setting Sun and moving into the evening sky.
April 20th: K1 PanSTARRS becomes circumpolar for observers above 45 degrees north until May 25th.
April 26th: Passes into the constellation Ursa Majoris.
April 29th: Passes the bright +1.9th magnitude star Alkaid in the handle of the Big Dipper asterism. This is the brightest star that K1 PanSTARRS will pass near for this apparition, and Alkaid will make a great “finder” to spot the comet.
April 29th: The Moon reaches New phase.
April 30th: Approaches the +4.7 magnitude star 24 Canum Venaticorum.
May 1st: Passes less than 2 degrees from the galaxy M51… photo op!
May 3rd: Passes the 5.1 magnitude star 21 Canum Venaticorum.
May 6th: K1 PanSTARRS Reaches a maximum declination of 49.5 degrees north.
May 11th: Passes the 5.3 magnitude star 3 Canum Venaticorum.
May 14th: Passes into the constellation Ursa Major.
May 17th: Another great photo ops awaits astrophotographers, as the comet passes the +3.7 magnitude star Chi Ursae Majoris and the +12 magnitude galaxy NGC 3877.
May 25th: Passes the 3rd magnitude star Psi Ursae Majoris.
May 28th: The Moon reaches New phase.
May 28th: Passes the 4.7 magnitude star Omega Ursae Majoris.
June 7th Passes into the constellation Leo Minor.
June 15th: Passes the +4.5 magnitude star 21 Leo Minoris.
June 22nd: Passes into the constellation Leo.
July 1- Passes to within 40 degrees elongation from the Sun.
And from there, Comet K1 PanSTARRS reaches perihelion just outside of the Earth’s orbit at 1.05 A.U. on August 27, and plunges south across the celestial equator on September 15.
Video animation of comet C/2012 K1 PanSTARRS over the span of an evening. Credit: Dan Crowson of Dardenne Prairie Missouri, used with permission.
It’s also worth noting that K1 PanSTARRS will make its first of two approaches at a minimum distance of 1.471 A.U.s from Earth May 4th and will be moving at about a degree a day – twice the diameter of the Full Moon – before receding from us once more for a closer 1.056 A.U. approach to Earth on August 25th.
Discovered on May 19th, 2012 by the PanSTARRS telescope based on the island of Maui, Comet K1 PanSTARRS was first spotted at 8.7 A.U.s distant, well past the orbit of Jupiter. The PanSTARRS survey has been a prolific discoverer of asteroids and comets, including the brilliant comet C/2011 L4 PanSTARRS that graced dusk skies in March of last year.
And those are just the binocular comets that are scheduled to perform… remember, the next “big one” could come barreling in towards the inner solar system at any time to put on a memorable performance worthy of another comet Hyakutake or Hale-Bopp… just not TOO close!
– Be sure to send those comet pics in to Universe Today.
Congratulations to Cristovao Jacques and the SONEAR team! On March 13 they snared C/2014 E2 (Jacques) in CCD images taken with a 0.45-meter (17.7-inch) wide-field reflector at the SONEAR (Southern Observatory for Near Earth Asteroids Research) observatory near Oliveira, Brazil. A very preliminary orbit indicates its closest approach to the sun will occur on June 29 at a distance of 56 million miles followed two weeks later by a relatively close flyby of Venus of 0.09 a.u. or 8.4 million miles (13.5 million km). If a comet approached Earth this closely so soon after perihelion, it would be a magnificent sight. Of course, watching from Venus isn’t recommended. Even if we could withstand its extreme heat and pressure cooker atmosphere, the planet’s perpetual cloud cover guarantees overcast skies 24/7.
It’s the team’s second comet discovery this year after turning up C/2014 A4 (SONEAR) in January. Comet Jacques has been tracking across northern Centaurus since discovery. Over the next few nights, it straddles the border with Hydra where it will be visible low in the southern sky around for northern hemisphere observers from about midnight to 2 a.m. If you live on a Caribbean island and points south your view will be even better.
Steven Tilley’s animation of Comet C/2014 E2 Jacques over 35 minutes on March 13, 2014
Comet Jacques exhibits a dense, fairly bright 2-arc-minute coma or cometary atmosphere with a short northward-pointing tail. Brightness estimates have been hard to come by, but it appears the comet may be around magnitude +11.5 – 12 or within range of an 8-inch (20-cm) or larger telescope. One thing’s for certain. In the coming weeks, E2 will be approaching both the Earth and the sun and brightening as it slowly gains altitude in the evening sky.
Shortly after perihelion, Comet Jacques will shine brightest at around magnitude +10-10.5 (though it could be brighter) and remain nearly this bright as it swings north from Orion into Perseus from mid-July to mid- August. Closest approach to Earth occurs on Aug. 29-30 at 54 million miles (87 million km). It will join Comet Oukameiden – predicted to reach binocular visibility in late August – to offer comet lovers much to look forward to as the summer wanes.