ESA Awakens Rosetta’s Comet Lander

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.

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.

Hello, world! ESA's Rosetta and Philae comet explorers are now both awake and well!
Hello, world! ESA’s Rosetta and Philae comet explorers are now both awake and well!

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.

Read more: Rosetta Spacecraft Spies Its Comet As It Prepares For An August Encounter

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:

Source: ESA’s Rosetta blog

Want to welcome Rosetta and Philae back on your computer? Download a series of ESA’s “Hello, World” desktop screens here.

Happy Equinox! – A Perfect Time to See the Zodiacal Light

Zodiacal light tilts upward from the western horizon and points at the Pleiades star cluster in this photo taken March 19, 2009. Clouds at bottom reflect light pollution from nearby Duluth, Minn. U.S. Credit: Bob King

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.  

The zodiacal (Zo-DIE-uh-cull) light is centered on the plane of the solar system called the ecliptic. On late March nights, you can trace it from near the western horizon more than 45 degrees (halfway up the sky). Stellarium
The zodiacal (Zo-DIE-uh-cull) light is centered on the plane of the solar system called the ecliptic. This is the same band of sky where you’ll find the planets and zodiac constellations, hence the name. On late March nights, you can trace it from near the western horizon more than 45 degrees (halfway up the sky). Created with Stellarium

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.

This image of coronal and zodiacal light (CZL) was taken by the Clementine spacecraft, when the sun was behind the moon. The white area on the edge of the moon is the CZL, and the bright is Venus. (Credit: NASA)
Photo of coronal and zodiacal light taken by the Clementine spacecraft when the sun was hidden by the moon. At right is Venus. Clementine measured the brightness of the light to arrive at an integrated magnitude of -8.5. It also estimated dust particle sizes and origin. Credit: NASA

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.

The combined glow of dust particles in the plane of the solar system reaching from the sun's vicinity to beyond Mars is responsible for creating the zodiacal light. Planets are shown as colored disks. Illustration: Bob King
The combined glow of dust particles in the plane of the solar system reaching from the sun’s vicinity out to at least Jupiter is responsible for creating the zodiacal light. Dust closest to the sun glow more brightly, the reason the bottom of the zodiacal light cone is brighter than the tip. Planets are shown as colored disks. Illustration: Bob King

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.

Scanning electron microscope photo of an interplanetary dust particle collected by a high-altitude plane. It measures about 8 microns across or a little less than twice the size of a human red blood cell. Scientists recently discovered that dust particles can act as tiny factories to built water molecules. Credit: Donald Brownlee and Elmar Jessberger
Scanning electron microscope photo of an interplanetary dust particle collected by a high-altitude plane. It measures about 8 microns across or a little less than twice the size of a human red blood cell. Scientists recently discovered that dust particles can act as tiny factories to built water molecules. Credit: Donald Brownlee and Elmar Jessberger

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.

Incredible 360-degree-wide view of morning and evening zodiacal light cones (far left and right), the fainter zodiacal band and the brighter spot of gegenschein. Click to enlarge. Credit: Miloslav Druckmuller and Shadia Habbal
Incredible 360-degree-wide view of morning and evening zodiacal light cones (far left and right), the fainter zodiacal band and the brighter spot of gegenschein (center) and the Milky Way photographed from Mauna Kea. Click to enlarge. Credit: Miloslav Druckmuller and Shadia Habbal

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 gegenschein, an oval shaped brighter spot within the faint zodiacal band, is easiest to when due south and highest in the sky at local midnight (1 a.m. Daylight Saving Time). Currently it's in northern Virgo. Since the 'counter glow' will always be opposite the sun, it will slide down closer to Spica in April. Created with Stellarium
The gegenschein, an oval shaped brighter spot within the faint zodiacal band, is easiest to when due south and highest in the sky at local midnight (1 a.m. Daylight Saving Time). Currently it’s in northern Virgo. Since the ‘counter glow’ will always be opposite the sun, it will slide down closer to Spica in April. Created with Stellarium

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.

Zodiacal light cones in the fall morning sky (left) and in late March. Both times of year, we see the plane of the solar system tipped at high angle in the sky. Credit: Bob King
Zodiacal light cones in the fall morning sky (left) and in late March. Both times of year we see the plane of the solar system tipped at a high angle in the sky. Credit: Bob King

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.

New Comet Jacques May Pass 8.4 million miles from Venus this July

Comet C/2014 E2 Jacques photographed from Siding Spring Observatory on March 14, 2014. Credit: Rolando Ligustri

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.

Comet Jacques travels across the deep southern sky in early spring as seen from mid-northern latitudes
Comet Jacques travels across the deep southern sky in early spring as seen from mid-northern latitudes. Approximate positions are shown through April 4. Stellarium

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.

Another view of the comet on March 13 through a 0.5-meter (19.5-inch) telescope. Credit: Ernesto Guido, Nick Howes, Martino Nicolini
Another view of the comet on March 13 through a 0.5-meter (19.5-inch) telescope. Credit: Ernesto Guido, Nick Howes, Martino Nicolini

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.

NEOWISE Spots a “Weirdo” Comet

Infrared image of comet NEOWISE (C/2014 C3). Credit: NASA/JPL-Caltech

NASA’s NEOWISE mission — formerly known as just WISE — has identified the first comet of its new near-Earth object hunting career… and, according to mission scientists, it’s a “weirdo.”

In its former life NASA’s WISE (Wide-field Infrared Survey Explorer) spacecraft scanned the entire sky in infrared wavelengths. It helped discover the galaxy’s coldest stars, the Universe’s brightest galaxies, and some of the darkest asteroids lurking in the main asteroid belt between Mars and Jupiter… as well as closer in to Earth’s neck of the woods.

After exhausting its supply of liquid coolant needed to shield itself from its own radiating heat, in 2011 WISE was put into a state of hibernation. It was awoken last year and rebranded NEOWISE, and set upon the task of locating unknown objects with orbits in the proximity of Earth’s.

Kevin Luhman discovered the brown dwarf pair in data from NASA's Wide-field Infrared Survey Explorer (WISE; artist's impression). Image: NASA/JPL-Caltech
Artist’s impression of the WISE satellite

To date several new asteroids have already been found by NEOWISE, and on February 14, 2014, it spotted its first comet.

“We are so pleased to have discovered this frozen visitor from the outermost reaches of our solar system,” said Amy Mainzer, NEOWISE principal investigator at JPL. “This comet is a weirdo — it is in a retrograde orbit, meaning that it orbits the sun in the opposite sense from Earth and the other planets.”

Designated “C/2014 C3 (NEOWISE),” the comet was 143 million miles (230 million km) away in the image above — a composite made from six infrared exposures. That’s 585 times the distance to the Moon, or about the average distance between the Earth and Mars.

The tail of the comet NEOWISE extends about 25,000 miles (40,000 km) to the right in the image.

Overall, C/2014 C3 (NEOWISE) was spotted six times before it moved out of range of the spacecraft’s view. The comet has a highly-eccentric 20-year orbit that takes it high above the plane of the Solar System and out past the orbit of Jupiter. Technically, with a perihelion distance greater than 1.3 AU, comet C/2014 C3 does not classify as a near-Earth object (and its orbit does not intersect Earth’s.) But it’s still good to know that NEOWISE is looking out for us.

Read more on JPL’s NEOWISE site here, and see details on the comet’s orbit on the Minor Planet Center’s website here and from JPL’s Small-Body Database here.

Source: NASA/JPL

Two Comets Pass in the Night Bound for Your Telescope

Spectacular photo of Comets C/2012 X1 LINEAR (top) and C/2013 R1 Lovejoy taken with a wide field 4-inch telescope before dawn Feb. 9, 2014. Credit: Damian Peach

Remember comets Lovejoy and C/2012 X1 LINEAR? We dropped in on them in late January. On Feb. 6 the two cruised within  2 degrees of each other as they tracked through Ophiuchus before dawn.  Were it not for bad weather, astrophotographer Damian Peach would have been out to record the cometary conjunction, but this unique photo, taken two mornings later, shows the two comets chasing each other across the sky. Of course they’re not really following one another, nor are they related,  but the illusion is wonderful.

Comets Lovejoy and X1 LINEAR are neighbors in northern Ophiuchus this month and next. This map shows the sky facing east about 1 hour 45 minutes before sunrise shortly before the start of morning twilight. Tick marks show the comets’ position every 5 days. Click to enlarge. Detailed map below. Created with Chris Marriott’s SkyMap software. Read more: http://www.universetoday.com/108569/lovejoy-and-x1-linear-comets-to-warm-up-your-mid-winter-mornings/#ixzz2slrnLMIx
Comets Lovejoy and X1 LINEAR are neighbors in northern Ophiuchus through Feb. 25. This map shows the sky facing east about 1 hour 45 minutes before sunrise shortly before the start of morning twilight. Tick marks show the comets’ position every 5 days. Detailed map below. Created with Chris Marriott’s SkyMap software.

Rarely do two relatively bright comets align so closely. Even more amazing was how much they looked alike. By good fortune I was able to see them both  through a 15-inch (37-cm) under a very dark sky this morning. Although Lovejoy’s faint, approximately 20′ long tail was fanned out more than X1’s, both tails were faint, short and pointed to the west-northwest. Lovejoy’s coma was slightly larger and brighter, but both comets’ comas diplayed similarly compact, bright centers.

This deeper map shows stars to about magnitude 8. Although both comets appear to be getting lower every morning, the westward seasonal drift of the stars will keep them in good view for the next few months. Click to enlarge. Created with Chris Marriott’s SkyMap software
This deeper map shows stars to about magnitude 8. Although both comets appear to be getting lower every morning, the westward seasonal drift of the stars will keep them in good view for the next few months. Click to enlarge. Created with Chris Marriott’s SkyMap software

Lovejoy currently hovers around magnitude 8.1, X1 LINEAR at 8.8 – less than a magnitude apart.  If you haven’t seen them yet, they’re still the brightest comets we’ll have around for another few months unless an unexpected visitor enters the scene.

After converging for weeks, the comets’ paths are now slowly diverging and separating. Look while you can; the waxing moon will soon rob these fuzzies of their fading glory when it enters the morning sky this coming Tuesday or Wednesday.

See this earlier article for more information on both comets.

Wake Up, Rosetta!

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.


It’s being called “the most important alarm clock in the Solar System” —  this Monday, January 20, at 10:00 GMT (which is 5:00 a.m. for U.S. East Coasters like me) the wake-up call will ring on ESA’s Rosetta spacecraft, bringing it out of hibernation after over two and a half years in preparation of its upcoming and highly-anticipated rendezvous with a comet.

The wake-up will incite the warming of Rosetta’s star trackers, which allow it to determine its orientation in space. Six hours later its thrusters will fire to stop its slow rotation and ensure that its solar arrays are receiving the right amount of sunlight. Using its thawed-out star trackers Rosetta will aim its transmitter towards Earth and, from 500 million miles (807 million km) away, will send a thumbs-up signal that everything is OK and it’s time to get back to work.

From that distance the transmission will take 45 minutes to reach us. Rosetta’s first signal is expected between 17:30 – 18:30 GMT (12:30 – 1:30 p.m. ET). Once we’re assured all is well, Rosetta has a very exciting year ahead!

After nearly a decade of soaring through the inner solar system, flying past Mars and Earth several times and even briefly visiting a couple of asteroids (2867 Steins on September 5, 2008 and 21 Lutetia on July 10, 2010) Rosetta is finally entering the home stretch of its mission to orbit the 4-km-wide comet 67P/Churyumov-Gerasimenko.

Once Rosetta enters orbit around the comet — the first time a spacecraft has ever done so — it will map its surface and, three months later in November, deploy the 220-lb (100-kg) Philae lander that will intimately investigate the surface of the nucleus using a suite of advanced science instruments. (Watch a video here of how all this will happen… using Legos!)

Read more: Spider-Like Spacecraft Aims To Touch A Comet Next Year After Rosetta Reactivates

With Philae firmly attached to the comet, Rosetta will follow it around the Sun as it makes its closest pass in August 2015 and then heads back out towards the orbit of Jupiter. Rosetta will provide the most detailed observations ever of a comet’s composition and dramatic evolution as it encounters the heat and energy of our home star.

Of course, before all this can happen Rosetta first has to… WAKE UP! It entered hibernation in July 2011 and has remained silent in a slow spin ever since, with only its computer and some heaters kept running. Waking up from a 31-month nap can’t be easy, so ESA is inviting people around the world to help Wake Up Rosetta (and possibly even win a trip to Germany for the landing in November) by sharing their short movies of how best to awaken a sleeping spacecraft and sharing them to the contest page on Facebook or to Twitter, Vine, or Instagram with the #WakeUpRosetta hashtag.

See more about the contest below:

Video submissions to the Wake Up Rosetta video contest will be accepted until 17:30 GMT on Monday so if you haven’t already, get your cameras out and your imaginations going… this spacecraft isn’t going to wake itself! (Well, actually it kinda is but you can still show off your creativity!)

And even if you don’t send in a video, you can watch the live feed of Monday’s events from ESA starting at 09:15 GMT (4:15 a.m. ET) here and here. (Also follow @ESA_Rosetta on Twitter — currently it’s “still sleeping.”)

Want to find out where Rosetta is right now? Check out this cool interactive map from Daniel Scuka, Senior Editor of Spacecraft Operations at ESOC.

Rosetta launched on March 2, 2004 by an Ariane-5 G+ from Europe’s spaceport in Kourou, French Guiana. Read more on the mission page and the Rosetta blog here.

___________

UPDATE Jan. 20: Rosetta has awoken! This afternoon at 18:18 UTC, after 48 minutes of increasingly tense anticipation, a signal from the spacecraft was received by both NASA’s Deep Space Network in Goldstone, CA and the ground station in Canberra, Australia. Rosetta is up and running and so far seems to be in good condition — Go Rosetta and Philae! Read the full story here.

Comets Prospects for 2014: A Look Into the Crystal Ball

Comet C/2013 R1 Lovejoy starts the new year as the brightest comet in the sky at around magnitude 6. In this photo taken on Dec. 31, two tails are visible. The longer one is the ion or gas tail; the broader fan is the dust tail. Credit: Damian Peach

As 2014 opens, most of the half dozen comets traversing the morning and evening sky are faint and require detailed charts and a good-sized telescope to see and appreciate. Except for Comet Lovejoy. This gift to beginner and amateur astronomers alike keeps on giving. But wait, there’s more. Three additional binocular-bright comets will keep us busy starting this spring.

Track of Comet C/2013 R1 Lovejoy in the morning sky marked at 3-day intervals shortly before the start of dawn (6 a.m. local time) tomorrow through Jan. 31. Stars shown for Dec. 29 to magnitude 5.8. Her = Hercules and Oph = Ophiuchus. Click to enlarge. Created with Chris Marriott's SkyMap software
Track of Comet C/2013 R1 Lovejoy in the morning sky marked at 3-day intervals shortly before the start of dawn (6 a.m. local time) tomorrow through Jan. 31. Stars shown for Dec. 29 to magnitude 5.8. Her = Hercules and Oph = Ophiuchus. Click to enlarge. Created with Chris Marriott’s SkyMap software

Still glowing around the naked eye limit at magnitude 6, the Lovejoy remains easy to see in binoculars from  dark skies as it tracks from southern Hercules into Ophiuchus in the coming weeks.

The best time to view the comet is shortly before the start of dawn when it sails highest in the eastern sky at an altitude of around 30 degrees or “three fists” up from the horizon. By January’s end, the comet will still be 25 degrees high in a dark sky. My last encounter with Lovejoy was a week ago when 10×50 binoculars revealed a bright coma and 1.5 degree long tail to the northwest. Through the telescope the stark contrast between bright, compact nucleus and gauzy coma struck me as one of the most beautiful sights I’d seen all month.

Path of Comet C/2012 K1 PANSTARRS this spring when it should be a nice comet for small to medium sized telescopes. Created with Chris Marriott's SkyMap software
Path of Comet C/2012 K1 PANSTARRS this spring when it should be a nice comet for small to medium sized telescopes. Created with Chris Marriott’s SkyMap software

Looking ahead to 2014 there are at present three comets beside Lovejoy that are expected to wax bright enough to see in binoculars and possibly with the naked eye: C/2012 K1 PanSTARRSC/2013 V5 Oukaimeden and C/2013 A1 Siding Spring  The first lurks in Hercules but come early April should bulk up to magnitude 9.5, bright enough to track in a small telescope for northern hemisphere observers. Watch K1 PANSTARRS amble from Bootes across the Big Dipper and down through Leo from mid-spring through late June hitting magnitude 7.5 before disappearing in the summer twilight glow. K1 will be your go-to comet during convenient viewing hours.

Come early September after K1 PANSTARRS leaves the sun’s ken, it reappears in the morning sky, traveling westward from Hydra into Puppis. Southern hemisphere observers are now favored, but northerners won’t suffer too badly. The comet is expected to crest to magnitude 5.5  in mid-October just before it dips too far south for easy viewing at mid-northern latitudes.

Comet Oukaimeden may glow around 8th magnitude in late August 2014 when it rises with the winter stars before dawn. Stellarium.
Comet Oukaimeden may glow around 8th magnitude in late August 2014 when it rises with the winter stars before dawn. Stellarium.

Comet C/2013 V5 (Oukaimeden), discovered November 15 at Oukaimeden Observatory in Marrekesh, Morocco. Preliminary estimates place the comet at around magnitude 5.5 in mid-September. It should reach binocular visibility in late August in Monoceros the Unicorn east of Orion in the pre-dawn sky before disappearing in the twilight glow for mid-northern latitude observers. Southern hemisphere skywatchers will see the comet at its best and brightest before dawn in early September and at dusk later that month.

Comet C/2013 A1 Siding Spring is currently a faint 14th magnitude object in Eridanus. Photo taken on Dec. 30, 2013. Credit: Rolando Ligustri
Comet C/2013 A1 Siding Spring is currently a faint 14th magnitude object in Eridanus. Photo taken on Dec. 30, 2013. Credit: Rolando Ligustri

2014’s most anticipated comet has to be  C/2013 A1 Siding Spring, expected to reach magnitude 7.5 and become binocular-worthy for southern hemisphere skywatchers as it traverses the southern circumpolar constellations this September. Northerners will have to wait until early October for the comet to climb into the evening sky by way of Scorpius and Sagittarius. Watch for an 8th magnitude hazy glow in the southwestern sky at that time.

As October ticks by, A1 Siding Spring creeps closer and closer to Mars until it overlaps the planet on the 19th. Normally, a comet will only appear to pass in front of stars and deep sky objects because it’s in the same line of sight. Not this time. Siding Spring may actually “touch” Mars for real.

Comet C/2013 A1 Siding Spring will overlap Mars on October 19, 2014. With the planet at magnitude
Comet C/2013 A1 Siding Spring will overlap Mars on October 19, 2014. Assuming magnitude 8 at the time, the comet should look like a hazy glow around the planet through binoculars and telescopes. Stellarium

On October 19 the comet will pass so close to the planet that its outer coma or atmosphere may envelop Mars and spark a meteor shower. The sight of a bright planet smack in the middle of a comet’s head should be something quite wonderful to see through a telescope.

While the list of predicted comets is skimpy and arguably not bright in the sense of headliners like Hale-Bopp in 1997 or even L4 PANSTARRS from last spring,  all should be visible in binoculars from a dark sky site.

Every year new comets are discovered, some of which can swiftly brighten and put on a great show like Comet Lovejoy (discovered Sept. 7) did last fall and continues to do. In 2013, 64 new comets were found, 14 of them by amateur astronomers. Comets with the potential to make us ooh and aah are out there –  we just have to find them.

Subaru Telescope Captures the Fine Details of Comet Lovejoy’s Tail

Comet C/2011 W3 (Lovejoy) imaged by the Subaru Telescope on Dec. 3. Image credit: NAOJ with data processing by Masafumi Yagi (NAOJ)

Comet ISON may be no more than just a cloud of icy debris these days but there’s another comet that’s showing off in the morning sky: C/2013 R1 (Lovejoy), which was discovered in September and is steadily nearing its Christmas Day perihelion. In the early hours of Dec. 3, astronomers using the 8.2-meter Subaru Telescope atop Mauna Kea in Hawaii captured this amazing image of Lovejoy, revealing the intricate flows of ion streamers in its tail. (Click the image above for extra awesomeness.)

According to a news story on the NAOJ website:

At the time of this observation, at around 5:30 am on December 3, 2013 (Hawaii Standard Time), Comet Lovejoy was 50 million miles (80 million km) distant from Earth and 80 million miles (130 million km) away from the Sun.

The entire image of comet Lovejoy was made with the Subaru Telescope’s Suprime-Cam, which uses a mosaic of ten 2048 x 4096 CCDs covering a 34′ x 27′ field of view and a pixel scale of 0.2”.

Where to find comet Lovejoy in the morning sky, Dec. 7 (via spaceweather.com)
Where to find comet Lovejoy in the morning sky, Dec. 7 (via spaceweather.com)

“Subaru Telescope offers a rare combination of large telescope aperture and a wide-field camera,” said a member of the observation team, which included astronomers from Stony Brook University in New York, Universidad Complutense in Madrid,  Johns Hopkins University, and the National Astronomical Observatory of Japan. “This enabled us to capture a detailed look at the nucleus while also photogenically framing inner portions of Comet Lovejoy’s impressive ion tail.”

Comet Lovejoy is currently visible in the early morning sky as a naked-eye object in the northern hemisphere.

Read more about Lovejoy’s journey through the inner solar system in this article by Bob King here.

Image of comet Lovejoy on Dec. 5 by Flickr user "Willo2173".
Image of comet Lovejoy on Dec. 5 by Flickr user Willo2173.

Do you have photos of comet Lovejoy or any other astronomical objects to share? Upload them to the Universe Today Flickr group!

NASA’s STEREO Spacecraft Spots Comets ISON and Encke

Comet ISON entered the STEREO scene with Encke on Nov. 21 (Credit: Karl Battams/NASA/STEREO/CIOC)

As comets ISON and Encke continue toward their respective rendezvous with the Sun, they have now both been captured on camera by NASA’s solar-observing STEREO spacecraft. The image above, taken on Nov. 21 (UT) with STEREO-A’s high-resolution HI-1 camera, shows ISON as it enters the field of view from the left. Encke is at center, while the planets Mercury and Earth (labeled) are bright enough to cause vertical disruptions in the imaging sensors. (The Sun is off frame to the right.)

As cool as this image is, it gets even better: there’s a video version. Check it out below:

Animation of STEREO-A images acquired on Nov. 20-21 (Karl Battams/NASA/STEREO/CIOC)
Animation of STEREO-A images acquired on Nov. 20-21 (Karl Battams/NASA/STEREO/CIOC)

The dark “clouds” coming from the right are density enhancements in the solar wind, causing all the ripples in comet Encke’s tail. (Source)

The position of NASA's STEREO spacecraft relative to Earth and the Sun on Nov. 22
The position of NASA’s STEREO spacecraft relative to Earth and the Sun on Nov. 22

It’s fascinating to watch how the solar wind shapes and affects the tail of comet Encke… as ISON moves further into view, I’m sure we’ll see similar disruptions in its tail as well. (And look what STEREO-A saw happen to Encke’s tail back in 2007!)

Encke reached the perihelion of its 3.3-year-long orbit on Nov. 21; newcomer ISON will arrive at its on Nov. 28. While it seems to be holding together quite well in these STEREO images, what happens when it comes within 730,000 miles of the Sun next week is still anybody’s guess.

Read more: Whoa, Take a Look at Comet ISON Now!