Seeing Earth’s origin through beer-goggles

The fifth largest meteorite ever found in East Antarctica was discovered in January 2013 by an international team of meteorite hunters. Antarctica makes an ideal hunting ground for meteorite huniting because of the cold, the movement of ice – which concentrates meteorites in certain regions – and high winds, which expose them to view. Credit: International Polar Foundation

Despite all the chatter about how important oxygen is (and it is), every day we breathe in far more nitrogen. Earth’s atmosphere is composed of 78% of the stuff compared to 21% oxygen. We know that the first photosynthesizing bacteria and later, plants, bulked up the air with O2, but where did all that N come from? Beer of course!

Bear with me.

Image of an actual protoplanetary disc surrounding the young star HL Tauri. The photo was made using multiple telescopes of the Atacama Large Millimeter Array (ALMA) and reveal possible positions of planets forming in the dark patchy rings within the system. The newly forming Sun and planets of our own solar system may have looked like this 4.6 billion years ago. Credit: ALMA (ESO/NAOJ/NRAO)

Earth’s nitrogen, like all the goodies that make our planet a rich and fascinating world, traces its origin back 4.56 billion years to the protoplanetary disk.

Within this enormous flattened disk of dust and gas, the planets, comets and asteroids formed through gravitational attraction, collision and re-assembly of ice-coated dust particles contributed by previous generations of stars, much of it from supernovae.

In a recent article in New Scientist Dennis Harries of the Friedrich-Schiller University in Jena, Germany describes rummaging through meteorites collected in Antarctica in the 1970s. Meteorites, particularly the stony variety called chondrites, contain minerals and gases from the original nebula that have been little altered since their origin.

In their study, Harries and colleagues turned up a brand new crystalline mineral composed of a rare combination of nitrogen and chromium which they named “carlsbergite” for the Carlsberg Foundation, an offshoot of the Danish brewery, which funded previous work on it. See, I told you this was about beer.

Diagram showing the ratio of the isotopes nitrogen-15 to nitrogen-14 on six different planets and moons. The moon, Earth and Venus have similar ratios while Mars and especially Saturn’s moon Titan have a larger amount of N-15 to N-14, suggesting their nitrogen came from somewhere else in the solar nebula – protoplanetary disk. Credit: NASA

Next, Harries measured the amount of different isotopes or varieties of nitrogen were present in the meteorites. Isotopes are two or more forms of the same element that have the same number of protons in their atomic nuclei but a different number of neutrons. Nitrogen-14, the most common form that makes up over 99% of known nitrogen, has 7 protons and seven neutrons. Other varieties exist like nitrogen-13 (with just 6 neutrons) and nitrogen-15 (8 neutrons).

The group discovered that mix of nitrogen isotopes was nearly identical to that found on Earth which suggests a common origin in the protoplanetary disk. Nitrogen’s pretty boring though. In its pure form it doesn’t react with anything, but when hooked up to three hydrogen atoms it makes quite a stink. We call it ammonia – chemical formula NH3.

Beer-inspired research bubbles on. Credit: Christian Horvat

Harries believes that dust grains afloat in the dusty disk may have been covered by thin shells of ice containing ammonia and other compounds. A large body, such as a newly-forming proto-planet, moving through the icy gas could have created a shock wave which heated the gas and evaporated the ice.

Now in vapor form, the chemicals could react together to form new materials including carlsbergite and possibly amino acids, where nitrogen is a key component. Somehow, somewhere the very first living things assembled amino acids into proteins. You gotta start somewhere.

Which brings me to a wish. Should the Coors Brewing Company decide one day to fund an investigation into meteorites and scientists uncover yet another new mineral, “coorslite” naturally comes to mind.

Best-ever pix of Ceres / Speedy asteroid courts tiny moon

This image, taken 147,000 miles (237,000 km) from Ceres on January 25, 2015 by NASA’s Dawn spacecraft, is part of a series of views representing the best look so far at the dwarf planet. It’s even better pictures of Ceres taken by the Hubble Space Telescope in 2003 and 2004. Credit: NASA/JPL-Caltech

Sit back and take in the view. You can see a new world coming into focus right before your eyes. The bright white spot, the origin of which is still unknown, stands out clearly, while dozens of craters lie at the limit of resolution. The new photos are 30 percent clearer than those taken with the Hubble in 2003 and 2004. Nothing like driving to the seen instead of staring at it from afar with a long lens.

This animation of the dwarf planet Ceres was made by combining images taken by NASA’s Dawn spacecraft on January 25, 2015. Credit: NASA/JPL-Caltech

We looked at Ceres only a week ago when Dawn was 91,000 miles farther out. While I’m not quite ready to sing the lyrics to the Jimmy Cliff song “I Can See Clearly Now”, it’s certainly a better picture.

This animation, created from 20 individual radar images, clearly show the rough outline of 2004 BL86 and its newly-discovered moon. Click for larger animation. Credit: NASA/JPL-Caltech

Speaking of things that spin, check out the radar movie made from images taken during yesterday’s flyby of asteroid 2004 BL86 by NASA’s Goldstone Radar facility in California. Wow, it has a moon! 2004 BL86 measures about 1,100 feet (325 meters) across while its moon is approximately 230 feet (70 meters) across.

Asteroid 2004 BL86 buzzes Earth as it crosses through Cancer last night. Time lapse by John Chumack

One interesting oddity. The moon appears to be revolving in an orbit perpendicular to that of the main body. Many moons orbit in or near the plane of the equator. Perhaps it’s an artifact of processing images created by radar pings. For more on the discovery, click HERE.

Shoot rockets at the aurora? Yes! Four launched overnight

A composite shot of all four rockets for the M-TeX and MIST experiments is made up of 30 second exposures. The rocket salvo began at 4:13 a.m. EST, Jan. 26, 2015, from the Poker Flat Research Range, Alaska. The white vapor clouds form from the release of trimethyl aluminum. Credit: NASA / Jamie Adkins

It was a good night at Poker Flat Research Range in Alaska last night. Conditions were go for the launch of four rockets straight into the northern lights near the fringe of Earth’s airy envelope. The goal? To study how auroral, radiation belt and energetic particles from the Sun affect the composition of the upper atmosphere.

Called the Mesosphere-Lower Thermosphere Turbulence Experiment, or M-TeX, and the Mesospheric Inversion-layer Stratified Turbulence, or MIST, each rocket released trymethyl aluminum (TMA), a liquid used as a tracer of upper atmospheric winds. When released into the air it turns into bright, white smoke.  Scientists at various ground stations photographed the evolving and expanding clouds of vapor to understand wind patterns in the rarefied regions where the aurora forms – usually 50-87 miles high. TMA vapor tracers do not pose a risk to health or the environment, according to NASA.

The M-TeX is prepared for vibration testing at NASA’s Wallops Flight Facility in Virginia.
Credit: NASA/Berit Bland

“Recent solar storms have resulted in major changes to the composition of the upper atmosphere above 49 miles (80 km), where enhancements in nitrogen compounds have been found,” said Richard Collins, M-TeX principal investigator from the Geophysical Institute at the University of Alaska, Fairbanks. ”These compounds can be transported into the middle atmosphere where they can contribute to ozone destruction.”

While the compounds can be transported to the lower atmosphere, it’s not a guarantee. That all depends on the roles of heating and turbulence produced by the onslaught of solar particles and radiation. That’s why scientists are doing the studies in the first place – to determine how materials in the upper atmosphere mix with those in the middle and what effect that might have on everything from air pollution to satellite drag.

Satellite drag is the retarding effect even the wispy air near the edge of outer space exerts in slowing down an orbiting satellite and changing its orbit. Large amounts of energy from auroras can heat the upper atmosphere, causing it to expand and increase satellite drag.

Launching rockets into the aurora. Audacious and sure to help us better understand how space weather affects our more meteorological variety.

All eyes will be on asteroid 2004 BL86 Monday night

Big boy asteroid 2004 BL86 will pass close enough to Earth tomorrow night (Jan. 26th) to show up in small telescopes. Credit: NASA

January’s been a busy month for skywatchers. Between bright comets, their outbursts and the recent triple shadow transit at Jupiter it’s finally time to catch our collective breath. Maybe hole up in the house and keep warm.

Banish the thought.

Monday night Jan. 26th an obscure asteroid with the moniker 2004 BL86 will make a relatively close pass of Earth, zipping by at 3.1 times the distance of the moon or some 750,000 miles (1.2 million km).

Not a big deal, right? At least once a month a space rock gets this close or closer. Except that this space rock isn’t your typical “tiny house”. 2004 BL86 is 2,230 feet (680 meters) across – more like a space mountain – and big enough and close enough to be easily visible in a small telescope. Even even a Wal-Mart scope will show it. No exaggeration.

This graphic shows the path of asteroid 2004 BL86 with its position shown for Jan. 19th. Closest approach to Earth occurs around 10 a.m (CST) Jan. 26th. The asteroid will fade after Monday but continue to be visible in modest amateur telescopes through about Jan. 29th. Click to see an animation. Credit: NASA/JPL-Caltech

At magnitude +9 under a dark sky the asteroid would be faintly visible with a pair of 10×50 binoculars, but the half moon will be out, so you’ll need a 3-inch or larger scope binoculars in the 15×70 range to spot it. The good news is that the object remains close to 9th magnitude from 6 p.m. to midnight (CST) with peak brightness around 10 p.m.

Discovered 11 years ago, hence the “2004″ prefix, 2004 BL86 is the largest asteroid to pass closest to Earth until 2027 when 1999 AN10 will beat it by coming within one lunar distance. This will also be the asteroid’s closest approach to our planet for at least the next two hundred years, so if you want to see it before you’re six feet under, now’s the time to put on a coat and toddle out the scope.

Map showing the hourly progress of 2004 BL86 Monday evening January 26th as crosses Cancer the Crab not far from Jupiter. Stars are shown to magnitude +9. Numbers at the tick marks show the time (CST) each hour starting at 6 p.m., then 7 p.m., 8 p.m. and so on. Click for a larger version. Created with Chris Marriott’s SkyMap program

All asteroids with well-determined orbits receive a number designation. The very first asteroid discovered, Ceres in 1801, got the #1 spot. Asteroid 13,683 Monty Python (no kidding) was discovered in August 1967. Our featured space mountain numbers 357,439 making its full designation (357439) 2004 BL86. If you’re looking for a new password, this is it.

Black stars-on-white version of the map above which you might find more useful. Click to see and download a large version.

OK, so let’s talk how to see this speeding “star”. Observers in the Americas, Europe and Africa will have the best seats when the asteroid shines brightest between 7 p.m. and midnight (CST) Monday night from a comfortably high perch in Cancer the Crab not far from the planet Jupiter.

Because 2004 BL86 will be near Earth it will be zipping along at the rate of about 2° or four moon diameters per hour. That means you’ll need to use detailed maps to find and track the asteroid as it moves in real time.

Notice that the 2004 BL86 passes near a couple relatively bright stars and even skirts the edge of the bright Beehive star cluster, also known as M44. These are good places to “lie in wait” for the object to move into the field of view. I usually pick a spot some minutes ahead of where the asteroid will be and familiarize myself with the star field. That way, when it arrives, it really stands out. Remember, you’ll be looking for a star-like object slowly crossing the field of view. In reality, it’s sailing by Earth at around 35,000 mph.

Detailed map showing stars down to magnitude +9.5. Click to see and print out a larger version. Created with Chris Marriott’s SkyMap software

Another thing to remember is that near-Earth asteroids will sometimes be a little bit off a particular track depending on your location. Not much but enough that I recommend you scan not just the single spot where you expect to see it but also nearby in the field of view. Just look for a “star” not plotted on the map and keep an eye on it for movement.

Once you nab your prey, follow it for 10, 15 or 30 minutes. It makes for good sport to watch it brush by stars along its path. The closer it comes to a star the more dramatic its apparent motion appears. You should also watch for changes in its brightness as the asteroid rotates. Depending upon shape and rotation rate (unknown at this point) asteroids can show large enough brightness variations to be seen visually at the telescope.

Radar images like these made of asteroid 2007 PA8 will also be made during 2004 BL86′s flyby. Click to enlarge. Credit: NASA/JPL-Caltech

You won’t be the only one watching. Astronomers plan to use NASA’s Deep Space Network antenna at Goldstone, California and the Arecibo Observatory in Puerto Rico to ping the asteroid with microwaves to generate images of it during the time around its closest approach. We hope to share those pictures as soon as they’re available.

As always, Dr. Gianluca Masi, Italian astrophysicist, will stream live coverage of the event beginning at 1:30 p.m. (19:30 UT) Monday. And don’t worry about Earth getting hit. Not only is this asteroid many thousands of miles away, but our planet’s gravity can’t “pull” it in because the beast is moving rapidly along its own orbit. At worst, Earth’s gravity may alter its orbit some. That’s it – so enjoy!

Triple shadow transit makes for triple the fun

Will Gator shot this excellent series of Jupiter portraits during different phases of the triple shadow transit last night and this morning with an 8-inch telescope. North is up and east to the left. In “D”, the top “dot” on the left side is the moon Callisto. The others are the shadows of (l-r) Europa, Callisto and Io. Credit: Will Gator

I had to dog last night’s triple shadow transit to see it but I’m glad I did. We had clouds nearly the entire time. But even with a crummy sky, Jupiter was bright enough to push through the ceiling at key times during the event.

Through the scope the planet drew a sharp profile with nice cloud belt detail. It was really fun to watch Io’s shadow catch up with and merge with Callisto’s shadow and then separate (panel C above). For a while the two looked like an headless ant or “negative double star”. Even more amazing was seeing the moon Io overlap Callisto’s shadow at 12:20 a.m.

For just a few minutes, Callisto’s black shadow turned a pale orange-gray, obviously lighter in tone than the neighboring shadow of Io. It simply looked wrong! Three minutes later Callisto returned as the biggest and most dominant shadow. Never seen anything like it.

When Europa squeezed onto the Jupiter’s disk at around 12:30 a.m. the show moved into high gear. It took a bit of concentration to see Europa as it casts the smallest shadow of the four Galilean moons. Just to its south, along the southern edge of the South Equatorial Belt, I could easily make out the moon Callisto. I managed about seven minutes of triple shadow viewing before the clouds became impenetrable.

After packing all the equipment away, I happily sat down and shared a glass of wine with my wife. Hope we’re all still around for 2032 when the next trifecta takes place.

Rare comet-moon conjunction tonight

Tonight (Friday, Jan. 23rd) the moon will pass only about 1°  (two moon diameters) south of Comet 15P/Finlay as seen from the Americas. This map shows the view from the upper Midwest at 7 p.m. Two 6th magnitude stars in Pisces are labelled. Created with Chris Marriott’s SkyMap software

I want to alert you to a rather unusual event occurring this evening.

If you read yesterday’s blog, you know about the triple shadow transit of Jupiter’s moons Io, Europa and Callisto. That’s scheduled for late tonight.

Earlier, around nightfall, the crescent moon will lie 1° or less to the south-southwest of comet 15P/Finlay. No doubt lunar glare will hamper the view some, but what a fun opportunity to use the moon to find a comet.

The farther south you live, the closer the moon will approach the comet tonight. This diagram shows the view from Tucson, Ariz. at nightfall when less than 1/2° will separate the two. At about the same time (~7 p.m. local time) the moon will occult or cover up a 6th magnitude star (seen poking out from its left side). Source: SkyMap

Finlay underwent a flare in brightness last week when it became easily visible in binoculars.

Though a crescent moon isn’t what you’d call a glare bomb, I can’t predict for certain whether you’ll still see the comet in binoculars tonight or need a small telescope instead. Most likely a scope. Finlay has faded some since its outburst and now glows around magnitude +8.5.

You can try with a 10×50 or larger glass, and if you don’t succeed, whip out your telescope; a 4.5-inch or larger instrument should handle the job. Just point it at the moon at star-hop a little to the north-northeast using the map until you see a fuzzy spot with a brighter center. That’s your comet. The tail won’t be visible unless you’re using more firepower, something closer to 10-inches.

Comet Finlay in outburst on January 20, 2015 showing a beautiful parabolic-shaped head. Credit: Joseph Brimacombe

By the way, the father south you live, the closer the moon approaches Finlay. From the far southern U.S. they’ll be just 1/2° apart. Keep going south and parts of Central and South America will actually see the earth-lit edge of moon approach and then occult the comet from view!

* UPDATE: Although light clouds marred the view I had difficulty finding the comet this evening in my 10-inch scope. It’s possible it’s further faded or my conditions weren’t optimal or both. No luck BTW in binoculars.

Guide to Friday’s rare triple moon shadow-blast on Jupiter

Shadow transit of Jupiter’s moon Io captured on January 8th this year. Late this Friday night, Io, Europa and Callisto will cast their shadows simultaneously on the planet in a rare triple shadow transit event. Credit: John Chumack

We’re down for a very rare event this weekend that won’t happen again until December 30, 2032 – at least across the Americas. Between 12:28 – 12:52 a.m. (CST) Saturday morning, Jupiter’s moons Io, Europa and Callisto will simultaneously cast shadows on the planet’s cloud tops. Naturally, you’ll need a telescope to see this but only a modest one. You can follow the entire show in a 4 1/2 inch or larger instrument magnifying around 75x.

As Galileo was the first to note, Jupiter’s four brightest moons – Europa, Io, Callisto and Ganymede – revolve about the planet like a solar system in miniature. Each has its own period of revolution ranging from 1.7 days for innermost Io to 16.7 days for more distant Callisto. The moons periodically pass behind the planet (and temporarily get hidden from view), off to one side where they pass through Jupiter’s shadow in eclipse and in front of the planet.

Simulation of Jupiter around 12:40 a.m. (CST) Saturday, January 24th. Two moons and all three shadows will appear projected against the planet’s pale white equatorial zone.
Created with WinJUPOS

When in front of Jupiter, the moons cast their own shadows on its cloud tops. Through a telescope they look like jet black pinpoints for the smaller satellites (Io, Europa) and small dots for Callisto and Ganymede. Amateur astronomers look forward to watching these black dots move across the Jupiter’s cloud belt in part because we’re watching an eclipse happening on another planet. Imagine if you were there within the shadow looking back toward the Sun. From that perspective the moon would cover the Sun in partial or total eclipse. Cool thought.

So here’s the deal. One shadow transit every so often isn’t unusual, two at the same time is more so and a triple happens on average only once or twice every decade. In a word, don’t miss this opportunity.

If you want to catch all three shadows, you’ve got 24 minutes between 12:28 and 12:52 a.m. (CST) Saturday morning January 24th. Before and after that slot, you’ll see the shadows of one or two of the moons but not all three. Below is a list of the CST times, with Universal or UT times in parentheses) when each shadow enters and exits the planet’s face. To convert to your time zone, add an hour for Eastern time, subtract an hour for Mountain and 2 hours for Pacific.

Friday night Jan. 23 – Saturday morning Jan. 24:

* Callisto’s shadow enters disk – 9:11 p.m. (3:11 UT)
* Io’s shadow enters disk – 10:35 p.m. (4:35 UT)
* Europa’s shadow enters the disk – 12:28 a.m. (6:28 UT)
** TRIPLE TRANSIT from 12:28 – 12:52 a.m. (6:28 – 6:52 UT)
* Io’s shadow leaves disk – 12:52 a.m. (6:52 UT)
* Callisto’s shadow leaves disk – 2:00 a.m. (8:00 UT)
* Europa’s shadow leaves disk – 3:22 a.m. (9:22 UT)

Jupiter at 11:52 p.m. (CST) Friday night when Io and Callisto’s shadows will appear to merge. Meanwhile, Io undergoes a partial eclipse in the shadow “beam” cast by Callisto. Source: WinJUPOS

This triple event is unique enough, but there’s even more happening in what I like to call the “pre-game show”. As each moon enters the planet’s face like actors in a play, their shadows will cross over and bump into one another. I’ve included diagrams showing what to expect. For more details on the triple play and special events leading up to it I hope you won’t mind clicking over to this article I wrote for Sky and Telescope online.

The pre-game show wraps up with the moon Io transiting over Callisto’s shadow around 12:20 a.m. CST. The change in the shadow’s appearance should be obvious to the eye. Source: WinJUPOS

Since it was overcast here for the last triple shadow transit in October 11-12, 2013 you can imagine how much I’d like to see clear skies this time around. 2032′s a long, long ways out.

Snake-tongued Comet Lovejoy slithers north, slowly fades

Right now Comet Lovejoy’s faint, double-rayed gas tail extends many degrees to the east of the bright coma. Observers using 10×50 and similar binoculars have traced it out to 10° or more. This photo was taken on Jan. 18th. Credit: Chris Schur

Forked tongues allow snakes to smell in stereo – each fork senses slightly different chemicals in the snake’s vicinity and feeds a separate signal to its brain. When combined, they create a complete “picture” of the reptile’s odiferous world. In much the same way, the two ears on opposite sides of our heard allow us to hear the world in rich stereo sound.

Comet Lovejoy’s nucleus is jetting gas and dust just like Comet 67P/Churyumov-Gerasimenko in this photo taken by the Rosetta spacecraft on November 22, 2014 from a distance of 18.6 miles (30 km). The nucleus is deliberately overexposed in order to reveal the faint jets of activity. Credits: A/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Lovejoy’s forked tail is hardly an operative organ, but it’s sure amazing sight for stereo eyes. Composed principally of carbon monoxide gas, each of the two primary rays is incredibly well-defined. Gases like water vapor, carbon monoxide and carbon dioxide boil off the nucleus as the Sun warms the comet and help create its big blue-green head or coma. As described here before, the solar wind ionizes or electrifies the gases which allows the magnetic fields embedded in the wind to peel back the gases to form a the glowing gas or ion tail.

Comet Lovejoy arcs up into Triangulum the Triangle later this week and continues into Andromeda into Cassiopeia. Northern hemisphere observers are favored, while those in the southern hemisphere will soon see the comet drop below their horizon. This chart shows Lovejoy’s position every 5 days around 7 p.m. (CST). Stars to magnitude +6. Click to enlarge. Created with Chris Marriott’s SkyMap software

I hope you’ve had the chance to see Comet Lovejoy. While the naked eye view isn’t impressive (though always a pleasure to behold any comet without optical aid), binoculars clearly show the faint, smoky tail extending east of the fuzzy head. In a telescope, even a fairly large one like the 15-inch (37-cm) reflector I use, the fainter rays are indistinct, though the forked tongue shows a little more clearly.

With the moon now returning to the evening sky (see below) and the comet starting to fade, it will gradually become more difficult to see with the naked eye. By mid-February, Lovejoy will probably have dimmed to the naked eye limit of around magnitude +6. But if you use binoculars, you’ll be able to follow our feathery friend through full moon and beyond.

The returning thin crescent moon gathers with brilliant Venus and fading Mercury low in the west-southwest sky during twilight this evening January 21st. This map shows the sky about 40-50 minutes after sunset. Stellarium

Northern skywatchers are fortunate that the comet continues to move north and ever higher in the sky. By late February it will be circumpolar from many locations and remain visible all night.

You can use the map to help you find Lovejoy as it climbs into Triangulum the Triangle this weekend and from there to Andromeda and Cassiopeia.

Mystery white spot revealed in Dawn’s new photos of Ceres

The Dawn spacecraft observed Ceres for an hour on Jan. 13, 2015, from a distance of 238,000 miles (383,000 km). A little more than half of its surface was observed at a resolution of 27 pixels. This animation, comprised of still images, shows bright and dark features and hints of craters. Ceres rotates once every 9 hours. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

Only 27 pixels across and yet this new image of Ceres by the Dawn spacecraft is nearly as sharp as those taken by the Hubble Space Telescope. To my eye it shows even more detail, possibly because the animation accentuates the changing shades of light so clearly, revealing the asteroid in three dimensions.

Besides uneven, possibly cratered terrain, what stands out is that bright, white spot. It’s also visible in the photos taken by the Hubble Space Telescope (below). Scientists aren’t sure yet what it is, but it may be water ice lining a crater floor. Interesting, eh?

Ceres, the largest asteroid (and also a dwarf planet) resides in the main asteroid belt between Mars and Jupiter. Here it’s compared to Mars, Mercury, the moon and Vesta, Dawn’s first target. Ceres is 590 miles (950 km) across and contains 30% of the mass of the entire main belt.  Credit: NASA

“Already, the (latest) images hint at the first surface structures such as craters,” said Andreas Nathues, lead investigator for the framing camera team at the Max Planck Institute for Solar System Research in Gottingen, Germany.

Hubble photos of Ceres taken in 2003-04 are slightly sharper – for now – than those from Dawn. Credit: NASA/ESA

These latest photos are just the first in a series that are taken for navigation purposes to refine the location of the asteroid and make sure Dawn spirals in accurately on its target. On March 6th, the probe will be captured by Ceres’ gravity; once in its embrace, Dawn will study this virtually unknown world-let for 16 months.

In this image, taken January 13, 2015, the Dawn spacecraft’s visible and infrared mapping spectrometer (VIR) captures dwarf planet Ceres in both visible and infrared light. The infrared image (right) serves as a temperature map of Ceres, where white is warmer and red is colder. Credit: NASA

We won’t have to wait long for even better photos - Dawn’s images will surpass Hubble’s resolution at the next imaging opportunity, which will be at the end of this month.

Single frame of Ceres taken by Dawn shows what appear to be the outlines of craters. Credit: NASA

Ceres is thought to have a rocky core overlain by an mantle of water ice and may even harbor a subsurface ocean. It’s the largest body between the Sun and Pluto that a spacecraft has not yet visited. Because it contains ice, Ceres is believed to have formed far from the Sun. Radioactive elements in minerals that went into building the asteroid helped to heat and partially melt its interior. Insulated by an icy crust estimated at more than 60 miles (100 km) thick, liquid water may yet lurk beneath its hard rind.


Mars has close brush with Neptune tonight

Binocular view (~5 field) of Mars, Neptune and nearby stars this evening. The planets will be very close together – only one-fifth of a full moon diameter apart. Mars is bright, but Neptune will look like a faint star to the planet’s upper right. Stars shown to magnitude +8.5. Source: Stellarium

Mars has been hiding away in Aquarius low in the southwestern sky at dusk minding its own business. But tonight however the Red Planet will pass VERY close to another more distant planet, Neptune.

To find Mars you’ll need an open view to the southwest. This map shows the sky facing southwest at the end of evening twilight. Mars is about 12-15° above the horizon at that time. Diphda is a fairly bright star in the constellation Cetus the Sea Monster. Source: Stellarium

You can see the “double planet” faintly in 10×50 or larger binoculars but a small telescope will make it a snap. The chart shows a binocular view just the way you’d see the scene facing southwest at nightfall with north toward the upper right. The best time to view the conjunction will be at the end of twilight when they’re highest.

Track of Mars in the next few days as it glides by the planet Neptune. This is also a 5° field of view similar to what you’d see in a pair of binoculars. Created with Chris Marriott’s SkyMap software

Also in your binocular view you’ll see the stars Sigma and 58 Aquarii. Neptune will look exactly like a star and surprisingly close to Mars.