Cosmic Journey by Sean McNaughton, Samuel Velasco, 5W Infographics, Matthew Twombly and Jane Vessels, NGM staff, Amanda Hobbs.
We humans are busy creatures when it comes to exploring the solar system. This new graphic (which updates one from four years ago) showcases all the planets we have visited in the past half-century. Both successful missions and failures are included on this updated list, although sadly you won’t find much about the various visits to comets and asteroids.
“The only downside to this spectacular map is the absence of orbits around minor bodies,” wrote Franck Marchis, a researcher at the Carl Sagan Center of the SETI Institute, in a blog post describing the graphic — which he often uses in public talks.
“Samuel Velasco, one of its creators, told me me that missions to asteroids and comets were not included because the graphic was getting too difficult to read. Tough choices had to be made.”
Other features of the graphic worth noting are the growing number of moon and Mars missions and the current locations of spacecraft in the outer solar system (or in Voyager 1’s case, beyond the solar system).
Explore the full resolution version by clicking on the lead image or here.
One of the highest-resolution images of Mercury's surface ever acquired.
Are you ready for a good close look at Mercury? At an incredible 5 meters per pixel, this is one of the highest-resolution images of Mercury’s surface ever captured. It was acquired on March 15 with the MESSENGER spacecraft’s MDIS (Mercury Dual Imaging System) instrument and shows an 8.3-km (5.2-mile) -wide section of Mercury’s north polar region, speckled with small craters and softly rolling hills.
Because MESSENGER was moving so quickly relative to the targeted area it was imaging, a short exposure time was necessary to avoid blurring. As a result the image appears a bit grainy. See the original map projection here.
Wondering what the next-best image was of Mercury? Find out below:
The previous record for most extreme close-up of Mercury was held by this image:
7 meter/pixel targeted observation of Mercury by the MESSENGER spacecraft
It was acquired as a targeted observation by MESSENGER’s Narrow-Angle Camera on April 30, 2012, and has a resolution of 7 meters/pixel. It shows an impact melt-covered area about 11 km (7 miles) across near Gaugin crater.
(Although Mercury’s surface may at first appear strikingly similar to the Moon’s, it’s been known since the Mariner 10 mission that the two worlds are very different at fundamental geologic and compositional levels. Read more on that here.)
Images like these are extremely special; during the first two years of MESSENGER’s mission in orbit around Mercury, over 150,000 images were acquired but only five images had resolutions better than 10 meters per pixel.
Artist’s impression of MESSENGER orbiting Mercury
On April 20, 2014, MESSENGER completed its 3,000th orbit of Mercury (3,075 to date) and is steadily moving into an even lower-altitude orbit. MESSENGER now comes within less than 200 km (124 miles) of the planet’s surface when it passes over its north pole every eight hours… that’s less than half the altitude of the Space Station!
Orbiting at such a low altitude and so often will allow MESSENGER to examine Mercury’s surface in unprecedented detail. Now that 100% of the planet has been successfully mapped by MESSENGER it can spend its second — and last — extended mission investigating specific scientific targets.
“The final year of MESSENGER’s orbital operations will be an entirely new mission,” said Sean Solomon, Principal Investigator for MESSENGER. “With each orbit, our images, our surface compositional measurements, and our observations of the planet’s magnetic and gravity fields will be higher in resolution than ever before. We will be able to characterize Mercury’s near-surface particle environment for the first time. Mercury has stubbornly held on to many of its secrets, but many will at last be revealed.”
Read more in a recent news release from the MESSENGER team here.
Want to explore a high-res map of Mercury and see where MESSENGER is right now? Click here.
Image credits: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Chalk up another benchmark in the fascinating and growing menagerie of extra-solar planets.
This week, an international team of researchers from the Université de Montréal announced the discovery of an exoplanet around the star GU Piscium in the constellation of Pisces the Fishes 155 light years distant. Known as GU Psc b, this world is estimated to be 11 times the mass of Jupiter — placing it just under the lower mass limit for brown dwarf status — and orbits its host star 2,000x farther than the distance from Earth to the Sun once every 80,000 (!) years. In our own solar system, that would put GU Psc b out over twice the distance of the aphelion of 90377 Sedna.
The primary star, GU Psc A, is an M3 red dwarf weighing in at 35% the mass of our Sun and is just 100 million years old, give or take 30 million years. In fact, researchers targeted GU Psc after it was determined to be a member of the AB Doradus moving group of relatively young stars, which are prime candidates for exoplanet detection. Another recent notable discovery, the free-floating “rogue planet” CFBDSIR 2149-0403 is also thought to be a member of the AB Doradus moving group.
The fact that GU Psc B was captured by direct imaging at 155 light years distant is amazing. The international team that made the discovery was led by PhD student at the Department of Physics Université de Montréal Marie-Ève Naud. The team was able to discern this curious planet by utilizing observations from the W.M. Keck observatory, the joint Canada-France-Hawaii Telescope, the Gemini Observatory and the Observatoire Mont-Mégantic in Québec.
An artist’s conception of the forlorn world of GU Psc b. Credit– Lucas Granito.
Universe Today recently caught up with researcher Marie-Ève Naud and her co-advisor Étienne Artigau about this exciting discovery.
What makes this discovery distinctive? Is this the most distant exoplanet ever imaged?
“Well, first, there are not a lot of exoplanets that were detected ‘directly’ so far. Most were found indirectly through the effect they have on their parent star. The few planets for which we have an actual image are interesting because we can analyze their light directly, and thus learn much more about them. It was also one of the “coolest” planets that have been directly imaged, showing methane absorption. And yes, it is certainly the most distant exoplanet to a main-sequence star that has been found so far.
This distance makes GU Psc b very interesting from a theoretical point of view, because it’s hard to imagine how it could have formed in the protoplanetary disk of its star. The current working definition of an exoplanet is based solely on mass (<13 Jupiter masses), so GU Psc b probably formed in a way that is more similar to how stars formed. It is definitely the kind of object that makes us think about what exactly is an exoplanet.”
At a distance of 2000 A.U.s from its primary, how are astronomers certain that PU Psc b is related to its host and not a foreground or background object?
“As the host star, GU Psc is relatively nearby; it displays a significant apparent proper motion (note: around 100 milliarcseconds a year) relative to distant background stars and galaxies.
On images taken one year apart with WIRCam on the Canada-France-Hawaii Telescope, we observed that the companion displays the same big proper motion, i.e. they move together in the plane of the sky, while the rest of the stars in the field don’t. We also determined the distance of the both the planet and the host star, and they both agree. Also, they both display signs that they are very young.”
Were any groundbreaking techniques used for the discovery, and what does this mean for the future of exoplanet science?
“Quite the opposite… most planet hunting techniques using direct imaging involve state-of-the-art adaptive optics systems, but we used ‘standard’ imaging without any exotic techniques. Planet searches usually attempt to find planets in orbits similar to those of our own solar system giants, and finding these objects, indeed, requires groundbreaking techniques. In a sense, there is an anthropocentric bias in the searches for exoplanets, as people tend to look for systems that are similar to our own solar system. Very distant planets like GU Psc b have been under the radar, even though they are easier to find than their closer-in counterparts. To find this planet, we used very sensitive ‘standard’ imaging, but we chose carefully the wavelengths where planets display colors that are unlike most other astrophysical objects such as stars and galaxies.”
The general field of GU Piscium A & B in the night sky… note that this currently puts it in the dawn sky, near Venus and Uranus! Credit: Starry Night.
GU Piscium shines at magnitude +13.6 northeast of the March equinoctial point in the constellation of Pisces. Although its exoplanet companion is too faint to be seen with a backyard telescope, its angular separation is a generous 42,” about the apparent span of Saturn, complete with rings. And it’s shaping up to be a red dwarf sort of week at Universe Today, with our recent list of red dwarf stars for backyard telescopes. And the current tally for extra-solar planets sits at 1,791… hey; didn’t we just pass 1,000 last year?
Congrats to Marie-Ève Naud and her team on this exciting new discovery… and here’s to many more to come!
British planetary scientist Colin Pillinger with the Beagle 2 lander.
British planetary scientist Colin Pillinger has passed away. Pillinger, age 70, was best known as leading the 2003 attempt to land the Beagle 2 spacecraft on Mars, part of the European Space Agency’s Mars Express mission.
His family said in a statement: “It is with profound sadness that we are telling friends and colleagues that Colin, whilst sitting in the garden yesterday afternoon, suffered a severe brain hemorrhage resulting in a deep coma. He died peacefully this afternoon at Addenbrooke’s hospital, Cambridge, without regaining consciousness … We ask that all respect our privacy at this devastating and unbelievable time.”
While the Beagle 2 spacecraft failed and likely crashed on Mars, the mission was notable because it was the first time an individual researcher had sent their own vessel into space and the first British-built interplanetary spacecraft. However, a lack of funding meant the Beagle 2 project always struggled. The spacecraft did launch, but all contact with Beagle 2 was lost after its separation from the Mars Express spacecraft, just six days before atmospheric entry.
However, the BBC noted that the mission was “a turning point in bringing together the space science and industrial communities in the UK – which didn’t used to speak with one voice. Beagle-2 wasn’t built in Colin’s backyard: it was the product of UK brains and hard-work in many companies and universities.”
Artist's impression of Beta Pictoris b. Credit: ESO L. Calçada/N. Risinger (skysurvey.org)
Between the time you got to work this morning and the time you leave today — assuming an eight-hour work cycle — an entire day will have passed on Beta Pictoris b, according to new measurements of the exoplanet.
This daily cycle, mapped for the first time on a planet outside of the solar system, may reveal a link between how big a planet is and how fast it rotates, astronomers stated. That said, caution is needed because there are only a handful of planets where the rotation is known: the eight planets of our Solar System and Beta Pictoris b.
The planet’s day is shorter than any other planet in our Solar System, which at first blush makes sense because the planet is also larger than any other planet in our Solar System. Beta Pictoris b is estimated at 16 times larger and 3,000 times more massive than Earth. (For comparison, Jupiter is about 11 times larger and 318 times more massive than Earth.)
“It is not known why some planets spin fast and others more slowly,” stated says co-author Remco de Kok, “but this first measurement of an exoplanet’s rotation shows that the trend seen in the Solar System, where the more massive planets spin faster, also holds true for exoplanets. This must be some universal consequence of the way planets form.”
Planets in our Solar system size comparison. Largest to smallest are pictured left to right, top to bottom: Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury. Via Wikimedia Commons.
Astronomers mapped the planet’s equatorial rotation using the CRIRES instrument on the Very Large Telescope. What helped was not only the planet’s large size, but also its proximity to Earth: it’s about 63 light-years away, which is relatively close to us.
As the planet ages (it’s only 20 million years old right now) it is expected to shrink and spin more quickly, assuming no other external forces. The Earth’s rotation is slowed by the moon, for example.
The study (“Fast spin of a young extrasolar planet” will soon be up on Nature’s website and was led by Leiden University’s Ignas Snellen.
Artist's impression of what the rings of the asteroid Chariklo would look like from the small body's surface. The rings' discovery was a first for an asteroid. Credit: ESO/L. Calçada/Nick Risinger (skysurvey.org)
Rings are a tough phenomenon to spot. As late as 1977, astronomers thought that the only thing in the solar system with rings was the planet Saturn. Now, we can add the first asteroid to the list of ringed bodies nearby us. The asteroid 10199 Chariklo hosts two rings, perhaps due to a collision that caused a chain of debris circling its tiny surface.
Besides the 250-kilometer (155-mile) Chariklo, the only other ringed bodies known to us so far are (in order of discovery) Saturn, Uranus, Jupiter and Neptune.
“We weren’t looking for a ring and didn’t think small bodies like Chariklo had them at all, so the discovery — and the amazing amount of detail we saw in the system — came as a complete surprise,” stated Felipe Braga-Ribas of the National Observatory (Observatório Nacional) in Brazil, who led the paper about the discovery.
Illustration of how Asteroid Chariklo may have gotten its rings. Copyright: Estevan Guzman for Universe Today.
The rings came to light, so to speak, when astronomers watched Chariklo passing in front of the star UCAC4 248-108672 on June 3, 2013 from seven locations in South America. While watching, they saw two dips in the star’s apparent brightness just before and after the occultation. Better yet, with seven sites watching, researchers could compare the timing to figure out more about the orientation, shape, width and more about the rings.
The observations revealed what is likely a 12.4-mile (20-kilometer)-wide ring system that is about 1,000 times closer to the asteroid than Earth is to the moon. What’s more, astronomers suspect there could be a moon lying amidst the asteroid’s ring debris.
Artist’s impression of two rings discovered around the asteroid Chariklo. It was the first such discovery made for an asteroid. Credit: ESO/L. Calçada/M. Kornmesser/Nick Risinger (skysurvey.org)
If these rings are the leftovers of a collision as astronomers suspect, this would give fodder to the idea that moons (such as our own moon) come to be from collisions of smaller bits of material. This is also a theory for how planets came to be around stars.
The rings haven’t been named officially yet, but the astronomers are nicknaming them Oiapoque and Chuí after two rivers near the northern and southern ends of Brazil.
Because these occultation events are so rare and can show us more about asteroids, astronomers pay attention when they occur. Part of the Eastern Seabord enjoyed a more recent asteroid-star occultation on March 20.
The original paper, “A ring system detected around the Centaur (10199) Chariklo”, will soon be available on the Nature website.
Artist’s impression of rings around the asteroid Chariklo. This was the first asteroid where rings were discovered. Credit: ESO/L. Calçada/M. Kornmesser/Nick Risinger (skysurvey.org)
Mars photographed during part of its rotation from Melbourne, Australia on March 8. The bright "cap" marks Hellas, now covered in wintertime frost and clouds. Credit: Maurice Valimberti
Earth’s changing weather always makes life interesting. Seeing weather on other planets through a telescope we sense a kinship between our own volatile world and the fluttering image in the eyepiece. With the April 8 opposition of Mars rapidly approaching, you won’t want to miss a striking meteorological happening right now on the Red Planet.
Map showing the most prominent dark features on Mars. Hellas is at upper right. Credit: A.L.P.O.
Winter’s already well underway in the planet’s southern hemisphere and there’s no better place to see it than over Hellas, Mars’ biggest impact crater. Hellas formed some 4 billion years when a small asteroid crashed into the young planet and left a scar measuring 1,400 miles (2,300 km) wide and 26,465 feet (7,152 meters) deep. Point your telescope in its direction in the next few weeks and you’ll see what looks at first like the planet’s south polar cap. Don’t be deceived. That’s Hellas coated in dry ice frost and filled with wintertime clouds.
The Hellas impact basin, also known as Hellas Planitia, is 1,400 miles wide. After Mars’ Utopia Planitia and the moon’s South Pole-Aitken Basin, Hellas is the third largest confirmed crater in the solar system.
Right now, Mars’ northern hemisphere, along with the north polar cap, are tipped our way. Though the cap is rapidly vaporizing as the northern summer progresses, you can still spot it this month as a small dab of white along the northern limb in 6-inch (15 cm) and larger telescopes. Use a magnification upwards of 150x for the best views. The south polar cap can’t be seen because it’s tipped beyond the southern limb.
Mars from Athens, Greece on March 14, 2014 with Hellas (top), Syrtis Major and both morning and evening limb water clouds. The winter-whitened Hellas impact basin is best seen using magnifications of 150x or higher. Credit: Manos Kardasis
Along with nearby Syrtis Major, Hellas was one of the first features discovered with the telescope. Even in summer its pale floor stands out against the darker volcanic features of the planet. Though windswept and bitter cold now, Hellas’ great depth makes it one of the warmest places on Mars during the summer months. Mid-summer atmospheric pressure has been measured at more than 10 millibars, more than twice the planet’s mean. Afternoon high temperatures reach near the freezing point (32 F / 0 C) with nighttime lows around -50 F (-45 C). Winter temperatures are much more severe with lows around -22o F (-140 C). Carbon dioxide condenses as frost and whitens the floors of many craters during this time.
Mars photographed by the Mars Global Surveyor shows the equally prominent Syrtis Major and the Hellas impact basin. Syrtis Major is an ancient, low relief shield volcano. Credit; NASA/JPL/Malin Space Systems
We can only see Hellas when that hemisphere is turned in our direction; this happens for about a week and a half approximately once a month. European observers are favored this week with Hellas well placed near the planet’s central meridian from 1 – 4 a.m. local time. Why the outrageous hour? Mars rises around 10 p.m. but typically looks soft and mushy in the telescope until it’s high enough to clear the worst of atmospheric turbulence 2 – 3 hours later. North and South American observers will get their turn starting this Saturday March 22nd around 12:30 – 1 a.m. Good Hellas viewing continues through early April.
Mars at 1 a.m. CDT on successive nights starting March 21, 2014. Notice how planetary features appear to rotate slowly eastward night to night. Created with images from Meridian
Like Earth, Mars revolves from west to east on its axis, but because it rotation period is 37 minutes longer than Earth’s, Hellas and all Martian features appear to drift slowly eastward with each succeeding night. A feature you observed face-on at midnight one night will require staying up until 2:30 a.m. a week later for Mars to “rotate it back” to the same spot. To keep track of the best times to look for Hellas or anything else on Mars, I highly recommend the simple, free utility called Meridian created by Claude Duplessis. Set your time zone and you’ll know exactly the best time to look.
Mars on March 8, 2014 shows clouds over Hellas and evening limb clouds. Credit: Chin Wei Loon
While you’re out watching the Martian winter at work, don’t forget to also look for the shrinking north polar cap and bright, patchy clouds along the planet’s morning (east) and evening limbs. You can use the map above to try and identify the many subtle, gray-toned features named after lands in classic antiquity by 19th century Italian astronomer and Mars aficionado Giovanni Schiaparelli.
I will you success in seeing Hellas and encourage you to share your observations with us here at Universe Today.
Meet Kepler-22b, an exoplanet with an Earth-like radius in the habitable zone of its host star. Unfortunately its mass remains unknown. Image Credit: NASA
Planet-watchers, some exciting news: you know how we keep talking about planet candidates, those planets that have yet to be confirmed, when we reveal stories about other worlds? That’s because verifying that the slight dimming of a star’s light is due to a planet takes time – -specifically, to have other telescopes verify it through examining gravitational wobbles on the parent star.
Turns out there’s a way to solve the so-called “bottleneck” of planet candidates vs. confirmed planets. NASA has made use of a new technique that they say will work for multi-planet systems, one that already has results: a single Kepler release of data today (Feb. 26) yielded 715 new planets in one shot. That almost doubles the amount of known planets found before today, which was just under 1,000, officials said.
“This is the largest windfall of planets, not exoplanet candidates, but actual verified exoplanets announced at one time,” said Doug Hudgins, a NASA exoplanet exploration program scientist based in Washington, D.C., at a press conference today. What’s more, among the release were four planets (about double to 2.5 times the size of Earth) that could be considered habitable: Kepler-174 d, Kepler-296 f, Kepler-298 d, Kepler-309 c.
The findings were based on scouring the first two of Kepler’s four years of data, so scientists expect there will be a lot more to come once they go through the second half. Most of the discoveries were planets close to Earth’s size, showing that small planets are common in multiplanetary systems.
These planets, however, are crowded into insanely compact multiple planet systems, sometimes within the reaches of the equivalent of Mercury’s or Venus’ orbits. It’s raising questions about how young systems would have enough material in those reaches to form planets. Perhaps planetary migration played a role, but that’s still poorly understood.
Verification by multiplicity is a new method for finding planets in multiple-planet systems. In cases where astronomers see several objects transiting a star in regular orbits, the assumption is it must be planets. A set of stars in a similar configuration would have orbits too unstable for regular transits. Credit: NASA
Discoveries of these worlds was made with a new technique called “verification by multiplicity”. The challenge with the method Kepler uses — watching for starlight dimming when a planet passes in front of it — is there are other ways that same phenomenon can occur. One common reason is if the star being observed is a binary star and the second star is just barely grazing the first.
This is how the technique works: If you can imagine a star with a bunch of other stars around it, the mutual gravities of each object would throw their relative orbits into chaos. A star with a bunch of planets, however, would have a more stable orbital configuration. So if scientists see multiple transits of objects across a star’s face, the assumption is that it would be several planets.
“This physical difference, the fact you can’t have multiple star systems that look like planetary systems, is the basis of the validation by multiplicity,” said Jack Lissauer, a planetary scientist at the NASA Ames Research Center who was involved in the research.
Although this is a new technique, the astronomers said there has been at least one published publication talking about this method, and they added that two papers based on their own research have been accepted for publication in the peer-reviewed Astrophysical Journal.
Sizes of verified planets just after a release of 715 confirmed planets from Kepler data in February 2014. Credit: NASA
There’s been a lot of attention on Kepler lately, not only because of its planetary finds, but also its uncertain status. In May 2013, a second of its four reaction wheels (or gyroscopes) went down, robbing the probe of its primary mission: to seek planets transiting in front of their stars in a spot in the Cygnus constellation. Since then, scientists have been working on a new method of finding planets with the spacecraft.
The spacecraft is good to go for K2 physically, NASA added, as the spacecraft only has four major malfunctions: the two reaction wheels, and 2 (out of 21) “science modules” that are used for science observing. The first module failed early in the mission, while the second died during a recent K2 test. While the investigation is ongoing, NASA said that they expect it will be due to an isolated part failure and that it will have no measurable impact on doing K2.
Edit, 8:30 p.m. EST: The two papers related to the Kepler discovery are available here and here on the prepublishing site Arxiv. Both are accepted for publication in the Astrophysical Journal. (Hat tip to Tom Barclay).
On Feb. 5, 1974, NASA's Mariner 10 mission took this first close-up photo of Venus during 1st gravity assist flyby. Credit: NASA
Exactly 40 Years ago today on Feb. 5, 1974, Mariner 10, accomplished a history making and groundbreaking feat when the NASA science probe became the first spacecraft ever to test out and execute the technique known as a planetary gravity assisted flyby used to alter its speed and trajectory – in order to reach another celestial body.
Mariner 10 flew by Venus 40 years ago to enable the probe to gain enough speed and alter its flight path to eventually become humanity’s first spacecraft to reach the planet Mercury, closest to our Sun.
Indeed it was the first spacecraft to visit two planets.
During the flyby precisely four decades ago, Mariner 10 snapped its 1st close up view of Venus – see above.
From that moment forward, gravity assisted slingshot maneuvers became an extremely important technique used numerous times by NASA to carry out planetary exploration missions that would not otherwise have been possible.
For example, NASA’s twin Voyager 1 and 2 probes launched barely three years later in 1977 used the gravity speed boost to conduct their own historic flyby expeditions to our Solar Systems outer planets.
Mariner 10’s Mercury.
This is a photomosaic of images collected by Mariner 10 as it flew past Mercury on 29 March 1974. It shows the southern hemisphere. The spacecraft took more than 7,000 images of Mercury, Venus, the Earth, and the moon during its mission. Credit: NASA
Without the flyby’s, the rocket launchers thrust by themselves did not provide sufficient interplanetary speed to reach their follow on targets.
NASA’s Juno Jupiter orbiter just flew back around Earth this past October 9, 2013 to gain the speed it requires to reach the Jovian system.
The Mariner 10 probe used an ultraviolet filter in its imaging system to bring out details in the Venusian clouds which are otherwise featureless to the human eye – as you’ll notice when viewing it through a telescope.
Venus surface is completely obscured by a thick layer of carbon dioxide clouds.
The hellish planet’s surface temperature is 460 degrees Celsius or 900 degrees Fahrenheit.
Diagram of Mariner 10 which flew by Venus and Mercury in 1974 and 1975. This photo identifies various parts of the spacecraft and the science instruments, which were used to study the atmospheric, surface, and physical characteristics of Venus and Mercury. This was the sixth in the series of Mariner spacecraft that explored the inner planets beginning in 1962. Credit: Jet Propulsion Laboratory
Following the completely successful Venus flyby, Mariner 10 eventually went on to conduct a trio of flyby’s of Mercury in 1974 and 1975.
It imaged nearly half of the planets moon-like surface, found surprising evidence of a magnetic field, discovered that a metallic core comprised nearly 80 percent of the planet’s mass, and measured temperatures ranging from 187°C on the dayside to minus 183°C on the nightside.
Mercury was not visited again for over three decades until NASA’s MESSENGER flew by and eventually orbited the planet – and where it remains active today.
Mariner 10 was launched on Nov. 3, 1973 from the Kennedy Space Center atop an Atlas-Centaur rocket.
Mosaic of the Earth from Mariner 10 after launch. Credit: NASAShortly after blastoff if also took photos of the Earth and the Moon.
Ultimately it was the last of NASA’s venerable Mariner planetary missions hailing from the dawn of the Space Age.
Mariner 11 and 12 were descoped due to congressional budget cuts and eventually renamed as Voyager 1 and 2.
The Mariner 10 science team was led by Bruce Murray of the Jet Propulsion Laboratory (JPL), Pasadena, Calif.
Murray eventually became the Director of JPL. After he passed away in 2013, key science features on Martian mountain climbing destinations were named in his honor by the Opportunity and Curiosity Mars rover science teams.
Stay tuned here for Ken’s continuing LADEE, Chang’e-3, Orion, Orbital Sciences, SpaceX, commercial space, Mars rover and more planetary and human spaceflight news.
Mariner 10 trajectory and timeline to Venus and Mercury. Credit: NASADiagram of the Mariner series of spacecraft and launch vehicle. Mariner spacecraft explored Mercury, Venus and Mars. Credit: Jet Propulsion LaboratoryMosaic of Earth from Juno gravity assist Flyby in 2013 –
compare to Mariner 10 Earth mosaic above from 1973 to see advances in space technology
This false color composite shows more than half of Earth’s disk over the coast of Argentina and the South Atlantic Ocean as the Juno probe slingshotted by on Oct. 9, 2013 for a gravity assisted acceleration to Jupiter. The mosaic was assembled from raw images taken by the Junocam imager. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo
Venus reflected in the Pacific Ocean late this fall seen from the island of Maui, Hawaii. The planet is now quickly dropping toward the sun. Credit: Bob King
I put down down the snow shovel to give my back a rest yesterday evening and couldn’t believe what I saw. Or didn’t see. Where was Venus? I looked to the south above the tree line and the goddess was gone! Sweeping my gaze to the right I found her again much closer to the western horizon point and also much lower.
As Venus revolves around the sun interior to Earth’s orbit, we see it pass through phases just like the moon. Tonight it’s still to the east of the sun (left side) and visible in the evening sky. On Jan. 11 it passes through conjunction and then appears on the other side of the sun in the morning sky. Illustration: Bob King
As 2013 gives way to the new year, Venus winds up its evening presentation as it prepares to transition to the morning sky. Catch it while you can. Each passing night sees the planet dropping ever closer to the horizon as its apparent distance from the sun shrinks. On January 11 it will pass through inferior conjunction as it glides between Earth and sun. Come the 12th, Venus nudges into the dawn sky – don’t expect to see it with the naked eye until around midmonth, when it’s far enough from the sun to bust through the twilight glare.
Phases of Venus during 2004 photographed through a telescope. When very close to inferior conjunction (bottom right) the crescent is seen to extend fully around the planet. Credit: Statis Kalyva / Wikipedia
Though the planet is departing, don’t let it disappear without at least a glance through binoculars. As conjunction approaches, Venus gets as close (and as large) as it can get to Earth and displays a most attractive crescent phase. Even 7x binoculars will show its thinning sickle shortly at dusk. Tonight (Dec. 27) Venus measures nearly 1 arc minute in diameter or 1/30 the width of the full moon and shines brightly at magnitude -4.5.
Venus is only about 12 degrees high in the southwestern sky some 20 minutes after sunset this evening Dec. 27. Stellarium
As the planet drops ever lower, the crescent grows both larger and thinner. A few days before conjunction, a telescope will show it extending beyond the usual 180-degree arc as sunlight beaming from behind Venus is scattered by the planet’s thick cloudy atmosphere.
When the air is transparent and seeing steady, amateur astronomers have photographed and observed the crescent wrapping a full 360 degrees around the planet’s disk – a sight quite unlike anything else in the sky.
Before Venus departs the evening sky, watch for it to pair up with a very thin crescent moon shortly after sunset on Jan. 2, 2014. Stellarium
In the coming week, watch for Venus starting about 15 minutes after sunset low in the southwestern sky. With each day, the planet becomes slightly less conspicuous as it competes against the twilight glow.
After final farewells late next week, we’ll look forward in the new year to welcoming the goddess in her new guise as morning star.
