This photo of Earth, showing the southern half of South America (upper right) is one of the first photos Juno sent home after its flyby. It was taken by the probe’s Junocam and methane filter at 2:06 p.m. CDT Oct. 9. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer
After a technical glitch that put the Jupiter-bound Juno space probe into “safe mode” after Wednesday’s Earth flyby, the probe is back to full health. This according to Ken Kramer of Universe Today.
NASA pre-programs spacecraft to put themselves in safe mode in case of unexpected technical troubles to prevent further problems down the line. No one knows what caused the snafu, but to the relief of all, Juno popped out of safe mode yesterday afternoon at 4:12 p.m. CDT and returned several early photos of Earth shot during the close encounter.
The flyby, which took the probe within 350 miles of the Earth’s surface, let Juno steal a bit of Earth’s gravitational energy to slingshot its way to Jupiter at a much higher speed. Juno gained some 16,330 mph (26,280 km/hr) after the close shave; the bending of its orbital path by Earth’s gravity targeted the spacecraft to within 1.24 miles (2 km) of its planned aiming point.
Well done NASA, well done. Read Ken’s complete story HERE.
41 five-second exposures of the rapidly moving spacecraft Juno photographed with an 11-inch telescope from Chelmsford, UK last night. Credit: Nick James
Juno got the gravity boost it needed to send it onward to its Jupiter encounter in July 2016 but not without a hitch. It whizzed just 350 miles above Earth’s surface yesterday afternoon, but when it emerged from the planet’s shadow into sunlight, scientists discovered the probe has put itself in “safe mode” to protect its instruments and systems.
While everything’s still running smoothly, engineers are trying to figure out what happened so they can get the craft back into normal operating mode. It’s uncertain whether Juno accomplished all its planned observations during the flyby which included taking pictures of the Earth-moon system and gathering information about Earth’s magnetic field and auroras. Hopefully we’ll know soon. One thing’s for sure – it remains on course to Jupiter.
When closest to Earth over South Africa Juno will be invisible in our planet’s shadow. It leaves the shadow and shines by reflected sunlight again just 18 minutes later. Observers and Asia and Europe might see it in small to medium-sized telescopes at the onset of night. Times shown are Pacific Daylight. Credit: Christ Peat / Heavens Above
Look! It’s a bird, it’s a plane, it’s … Juno! The Juno spacecraft will make an extremely close pass of Earth en route to its ultimate goal, the planet Jupiter. At 4:21 p.m. Central Daylight Time the probe will pass just 347 miles (559 km) from the ground while sailing over the southern tip of Africa at the incredible speed of 25 miles per second relative to the sun.
Juno, which spans about one bus length, has large solar arrays to convert sunlight into the electricity it needs to power its instruments. Credit: NASA
The close shave is deliberate – Juno will pick up an additional 16,330 mph of speed as it steals a bit of Earth’s orbital energy during the flyby. NASA’s been using “gravitational assist” since the Mariner 10 flybys of Venus and Mercury in 1973. Outer planet probes Voyager 1 and 2 leapfrogged their way across the solar system thanks to speed boosts from Jupiter, Saturn, and in the case of Voyager 2, Uranus. The method saves time and reduces energy requirements for space missions. Best of all – it’s free!
Juno’s trajectory to Jupiter. Credit: NASA;/JPL
Juno won’t be twiddling its thumbs during the flyby. NASA has programmed it to make a movie of the Earth-moon system showing the Earth spinning on its axis – the first time ever we’ll see our planet rotating from a distance. The craft will also make brief studies of Earth’s magnetosphere, the protective magnetic envelope surrounding the planet.
No one’s sure how bright the spacecraft might become. Most estimates I’ve seen put it around magnitude 9 at closest approach, making it easily visible in a small telescope if you know exactly where to look.18 minutes after its closest approach, Juno leaves Earth’s shadow and comes into view for observers in Europe and Asia, when it will be moving through the constellation Perseus. By then it will have faded to about magnitude 14 but possible glints from its large solar panels could create brighter flares.
When darkness falls over North America Juno will still be in Perseus but a magnitude fainter. That’s a tough find for visual observers with larger scopes but within reach of amateur astrophotographers. Again, these estimates are approximate. Juno could be brighter or dimmer.
The Slooh telescope will track Juno live starting at 8:30 p.m. tonight Central time. Click image to check it out. Credit: Slooh
Since most of us won’t be able to see this faint flyby from our backyards, others have generously come to the rescue. The Slooh telescope in the Canary Islands will broadcast live video of Juno tonight beginning at 8:30 p.m. CDT. Ham radio operators can also say hello to the probe in Morse cod by participating in Say ‘HI’ to Juno!
Amateur astronomer Scott Degenhardt will webcast Juno live from his home in New Mexico during two time slots: 1:45-2:45 a.m. and 4:15–5:15 a.m. tomorrow morning Oct. 10. Scott mentioned in an e-mail that bad weather might be coming, so if he’s offline, you’ll know why.
Learn more about the Juno mission in this video
Once Juno departs the Earth’s vicinity it’s in for a long cruise to Jupiter nearly half a billion miles away. Not until it enters Jupiter orbit in July 2016 will Juno see another planet so close. Click HERE to find out more its mission.
As Juno speeds past Earth next week it will pick up an extra 16,000 mph to boost it on its way to the planet Jupiter. The probe arrives at the solar system’s largest planet in July 2016. Credit: Bob King
Next Wednesday Oct. 9, the Juno spacecraft will make an extremely close approach to Earth as part of a gravity assist maneuver to boost to it to Jupiter. The probe was launched on Aug. 5, 2011 on a mission to look deep inside the planet below the swirling clouds that make Jupiter a favorite target for beginning astronomers.
Jupiter is covered in clouds that reach thousands of miles down into its atmosphere. In this artistic view, we’re looking up from between clouds into a clearing. Credit: Ron Miller
Juno will focus on the composition of Jupiter’s core, how much water saturates its lower level clouds, clock wind speeds at great depth and examine the planet’s vast magnetosphere, a bubble of magnetism spun to high speed by Jupiter’s rotation and laced with subatomic particles that buzz like angry bees. Most of particles are spewed by volcanic eruptions from the moon Io and spawn powerful auroras.
After its flyby of Earth, Juno continues cruising toward Jupiter, entering orbit there in the summer of 2016. Credit: NASA
Most spacecraft launched these days are not sent directly to their targets but loop by planets like Earth and Venus to pick up additional speed free of charge. Well, not exactly free. As Juno slingshots by Earth it will gain energy and velocity from the encounter but rob Earth of a tiny bit of its orbital energy. A gravitational assist both changes the direction of a spacecraft and pumps up its speed, saving time and propellant.
Video of Juno’s flyby of Earth on Oct. 9
A gravity assist can speed up a spacecraft if it flies with the movement of the planet or decelerate if it flies against the direction of its movement.
Will we see it? Probably not. The spacecraft’s closest approach occurs while in Earth’s shadow off the southern coast of Africa. The ground-track then heads northeast toward India before turning west to cross southern Europe. Observers there might catch it in binoculars if they know exactly where to look.
The spacecraft buzzes over North America the night of Oct. 9-10. It will be departing Earth’s vicinity at that time and probably be too faint for small telescopes but not for astrophotographers and amateurs with larger scopes.
The Mars MAVEN mission will continue as planned unaffected by the U.S. government shutdown. Credit: Bob King
NASA’s next Mars mission called MAVEN (Mars Atmosphere and Volatile EvolutioN) had been put on hold during the U.S. government shutdown. This raised the possibility that it might have missed its launch window (Nov. 18 – Dec. 7) depending on how long it the impasse might continue. But earlier this week it was determined that the mission provided a crucial communications link to help relay signals from Earth to the Curiosity and Opportunity rovers, making the spacecraft available for emergency funding. We’re back in business!
MAVENwill begin orbiting Mars next September to study its current climate to shed light out how the planet evolved into its current cold, dry state. Nice to get some good news.
Asteroid 2012 DA14, which will pass about 17,200 miles from Earth tomorrow (Fri. Feb. 15) around 1:24 p.m. CST is about 150 feet long or somewhat less than half the length of a football field. Illustration: Bob King using wiki and NASA images
As asteroid 2012 DA14 silently flies toward Earth, how would you like to go along for the ride? Now you can, virtually speaking. NASA has created a simulated display that allows you to accompany the asteroid as it speeds toward the planet. Since the view refreshes every two minutes, you can watch the planet grow larger as the asteroid sweeps in to make its closest approach tomorrow around 1:24 p.m. Central Time. That’s when the real drama will unfold as 2012 DA14 passes just 17,200 miles over Indonesia before speeding back into the depths of space. Click HERE to make the trip.
Although 2012 DA14 won’t impact Earth, the planet’s gravity will leave a potentially strong impression on the asteroid. Besides bending its orbit into a smaller circle with a shorter orbital period during the flyby, it’s possible that the space rock might tremble with tremors or asteroid-quakes.
View from the virtual asteroid tracker looking toward Earth today Feb. 14, 2013 at 1:37 p.m., one day before closest approach. Credit: NASA
“We are going to be looking closely for evidence of seismic activity on 2014 DA14 as it passes by,” says Richard Binzel, a professor of planetary science at MIT. “This is the first case of an object coming close enough to experience quakes AND where we have enough notice to plan observations.”
The Galileo spacecraft captured this “stretched color” view of asteroid 951 Gaspra in 1991. The red color is caused by solar radiation and cosmic rays weathering of the asteroid’s soil. Credit: NASA
A few years ago Binzel noticed a small group of asteroids that didn’t show signs of “space weathering” from bombardment by cosmic rays and solar radiation over the eons. High-energy particles interact with asteroids’ rocky surfaces and cause their soils to turn dark-red.
After studying their orbits, he discovered that all these “fresh-faced” space rocks had had close encounters with the Earth in the past million years.
“We believe they were ‘shaken up’ by their encounters with Earth,” he says. “Gravitational forces during the flybys can stretch, rattle, and torque these asteroids, causing dark, space-weathered material on the surface to be overturned, revealing the fresh stuff underneath.”
NASA’s Goldstone radar dish in California will have its eye trained on the asteroid during tomorrow’s flyby. The dish sends radio waves at the asteroid and measures their echo or reflection upon return to build up a map of its shape. Credit: NASA
2012 DA14′s crust could shift by an inch or two and possibly release a puff of asteroid dust. MIT postdoc Nick Moskovitz, who works with Binzel, is coordinating observations with worldwide observatories to pin down the color, spin, shape, and reflectivity of the asteroid as it passes by. NASA’s 70-meter Goldstone radar dish will also repeatedly ping 2012 DA14 with radio waves and measure the energy reflected back to create a 3D picture of it. If we’re very fortunate, the dish might even see the effects of seismic activity. Read more on the topic HERE.
Nice video about the flyby from NASA’s ScienceCast
A good near-Earth asteroid explainer after you get through the commercial
Looks like we all survived the whiz-by of two asteroids moving in unrelated orbits yesterday. 2010 RX30 is about 32-65 feet across and flew some 154,000 or 0.6 the distance of the moon from Earth, while the smaller 2010 RF12 ( 20-46 feet) passed even closer at just 49,000 miles. Despite their closeness, both were very faint objects visually with magnitudes around 15-16. Both were discovered on September 5 by the Catalina Sky Survey based near Tuscon, Arizona. I find it amazing that such tiny objects can be picked up at all. Scientists estimate there are something like 50 million house-sized asteroids orbiting the sun in the vicinity of our planet with an average of one a day passing between us and the moon. From this population, one every ten years would be expected to hit our atmosphere and possibly survive its plunge to the ground in the form of meteorites.
If you’ve got a couple minutes and want to find out what kind of destructive force asteroids of a particular size and consistency have, check out the Impact Calculator. The user-friendly interface lets you choose size, impact angle, speed and more, and then outputs the crater size, depth and magnitude of the quake created. It’s a good way to get to know the dark side of these seemingly innocent star-like objects we watch creep across the night sky with our telescopes.
Comet Hartley 2 photographed through an 8-inch telescope this past weekend. The comet is currently in the evening sky in Andromeda and visible in 6-inch and larger telescopes. By early next month it will be bright enough to see in binoculars. Credit: Michael Jaeger
As long as we’re on the topic of flying rocks, NASA’s Deep Impact probe, the one that flung an 815-lb. hunk of copper into the Comet Tempel 1 on July 4, 2005 in order to study to study the aftermath of the impact, has begun a new mission to study Comet Hartley 2. Like Tempel 1, Hartley 2 is a periodic comet, one that goes around the sun in a relatively short period of time. Hartley, discovered by Malcolm Hartley in 1986, completes an orbit in 6 1/2 years; this fall it will pass near the Earth and become as bright as 5th magnitude during late October and early November, making it an easy binocular comet. Cross your fingers – it might be bright enough to see with the naked eye.
Artist's view of Deep Impact at Tempel 1 in 2005. Comet Hartley 2's core or nucleus is small by cometary standards, measuring only about 1/2 mile across. Comets are small bodies like asteroids but composed of a mixture of dust and ice. Credit: NASA
Since 2005, Deep Impact has been on an extended mission called EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation), and its target for the next 79 days is Hartley 2. Last Sunday it beamed its first photo of the comet to Earth, one of more than 64,000 pictures the probe will take during the mission. The flyby and closest approach to the comet will occur on November 4 which turns out to be the same time it’s best viewed here on Earth. We can look forward to seeing closeups of the what’s at the center of all that cometary fuzziness while at the same time following it in our binoculars. Very cool. Scientists will use the craft’s two camera-equipped telescopes for photography and an infrared spectrometer to study the comet’s makeup. In the coming weeks, I’ll provide easy-to-use maps so you can find Comet Hartley 2 for yourself. Read more about the comet HERE.