Posted on by David Dickinson

NEO Asteroid 2014 JO25 Set to Buzz Earth on April 19th

Artist's concept of a large asteroid passing by the Earth-Moon system. Credit: A combination of ESO/NASA images courtesy of Jason Major/Lights in the Dark.
Missed us… a concept image of a large asteroid passing by the Earth-Moon system. Credit: A combination of ESO/NASA images courtesy of Jason Major/Lights in the Dark.

It’s a shooting gallery out there. The spattered face of Earth’s Moon and large impact sites such as Meteor Crater outside of Flagstaff, Arizona remind us that we still inhabit a dangerous neck of the solar neighborhood. But despite the inevitable cries proclaiming the “End of the World of the Week” this coming weekend, humanity can breathe a collective sigh of relief next Wednesday on April 19th, when asteroid 2014 JO25 passes safely by the Earth.

To be sure, lots of smaller space rocks pass by the Earth closer than the Moon (that’s an average of 240,000 miles distant) on a monthly basis. Take for example 4-meter asteroid 2017 GM, which passed just 16,000 kilometers distant on April 4th. What makes 2014 JO25 special is its size: measurements from NASA’s NEOWISE mission suggest that 2014 JO25 is about 2,000 feet (650 meters) along its longest axis, about twice the length of a Nimitz-class aircraft carrier. 2014 JO25 is passing 1.1 million miles (1.8 million kilometers) or 4.6 times the Earth-Moon distance on Wednesday, the closest large asteroid pass since 5-km Toutatis in September, 2004. The next predicted large asteroid pass near Earth is 1999 AN10, set to pass 1 LD (lunar distance) from the Earth in 2027.

4179 Toutatis as seen from China’s Chang’e 2 spacecraft. Credit: CNSA

This is also the closest passage of 2014 JO25 near the Earth for a 900 year span.

Discovered on May 5th, 2014 by the Catalina Sky survey, asteroid 2014 JO25 orbits the Sun once every three years, taking it from a perihelion of 0.237 AU (interior to Mercury’s orbit) out to an aphelion of 3.9 distant in the asteroid belt, interior to Jupiter’s orbit.

The orbit of NEO asteroid 2014 JO25. Credit: NASA/JPL.

Finding 2014 JO25 at its Closest Approach

With an estimated albedo (surface brightness) about twice that the lunar surface, 2014 JO25 will reach magnitude +10 to +11 on closest approach on Wednesday. Currently low in the dawn sky in the Square of Pegasus asterism, asteroid 2014 JO25 passed perihelion sunward as seen from the Earth at 1.015 Astronomical Units (AU) distant on March 11th. At its closest to the Earth on April 19th at 12:24 Universal Time (UT)/6:24 AM EDT, asteroid 2014 JO25 will skim the jagged Draco-Ursa Minor border below the bowl of the Little Dipper, moving at a whopping three degrees per hour. Sitting just 25 degrees from the north celestial pole on closest approach, catching sight of 2014 JO25 at favors western North America and northeastern Asia, though the eastern half of North America and Europe have a shot at the asteroid a few hours prior to closest approach in the early morning hours of April 19th. North American viewers get another shot at catching the fleeting asteroid later the same evening 13 hours after closest approach as the asteroid sails through the galaxy-rich constellation Coma Berenices.

The 24 hour path of asteroid 2014 JO25 from midnight UT April 18th through April 19th. (note: hourly time hacks are in Eastern Daylight Saving Time EDT UT-4). Credit: Starry Night Education software.

At +11th magnitude, you’ll need a telescope of at least 6” aperture or larger and a good star chart to nab 2014 JO25 as it glides against the starry background. Fellow Universe Today contributor Bob King has some great star charts of the pass over at Sky & Telescope. The Moon will be at Last Quarter phase on the morning of the 19th, providing moderate light pollution.

Plans are also afoot for NASA to ping asteroid 2014 JO25 using Arecibo and Goldstone radar… expect stunning animations to follow next week.

Clouded out? The good folks at the Virtual Telescope Project have you covered, with a live webcast featuring the passage of NEO 2014 JO25 starting at 21:30 UT/5:30 PM EDT on April 19th.

And if you’re out hunting for asteroids on the coming mornings, there are currently two bright binocular comets in the dawn sky to keep you company: Comet C/2017 E4 Lovejoy in the constellation Andromeda and Comet C/2015 ER61 PanSTARRS in Aquarius. Both are currently performing above expectations at about magnitude +7.

A busy neighborhood: Known asteroids as of April 1st, 2016. Credit: NASA/JPL.

“What if” an asteroid the size of 2014 JO25 hit the Earth? Well, the Chelyabinsk meteor was an estimated 20 meters in size; the impactor that formed Meteor Crater in Arizona was about 50 meters in diameter. The Chicxulub event off the Yucatan peninsula 66 million years ago was an estimated 10 kilometer-sized impactor well over ten orders of magnitude bigger than 2014 JO25. While the impact of a 600 meter asteroid would be a noteworthy event and a bad day locally, it would pale in comparison to an extinction level event.

All something to consider, as you watch the faint dot of asteroid 2014 JO25 pass harmlessly by the Earth and through the news cycle for the coming week.

Posted on by Nancy Atkinson

Asteroid Toutatis Tumbles in New Video from NASA

NASA has compiled the radar images taken of Asteroid Toutatis during its flyby of Earth this week to create a short movie, which shows the asteroid slowly tumbling. The 64-frame movie was generated from data gathered on December 12 and 13, 2012 by NASA’s 70-meter Goldstone Deep Space Network antenna in Goldstone, California.

NASA provides more information about the video and (4179) Toutatis:

On Dec. 12, the day of its closest approach to Earth, Toutatis was about 18 lunar distances, 4.3 million miles (6.9 million kilometers) from Earth. On Dec. 13, the asteroid was about 4.4 million miles (7 million kilometers), or about 18.2 lunar distances.

The radar data images of asteroid Toutatis indicate that it is an elongated, irregularly shaped object with ridges and perhaps craters. Along with shape detail, scientists are also seeing some interesting bright glints that could be surface boulders. Toutatis has a very slow, tumbling rotational state. The asteroid rotates about its long axis every 5.4 days and precesses (changes the orientation of its rotational axis) like a wobbling, badly thrown football, every 7.4 days.

The orbit of Toutatis is well understood. The next time Toutatis will approach at least this close to Earth is in November of 2069, when the asteroid will safely fly by at about 7.7 lunar distances, or 1.8 million miles (3 million kilometers). An analysis indicates there is zero possibility of an Earth impact over the entire interval over which its motion can be accurately computed, which is about the next four centuries.

This radar data imagery will help scientists improve their understanding of the asteroid’s spin state, which will also help them understand its interior.

The resolution in the image frames is 12 feet (3.75 meters) per pixel.

Source: NASA

Posted on by Nancy Atkinson

Asteroid Toutatis Tumbles by Earth: Images and Videos

Goldstone delay-Doppler radar images of Toutatis from December 11, 2012. Credit: NASA

While Asteroid 4179 Toutatis was never a threat to hit Earth during its quite-distant pass on Dec. 11-12, astronomers were keeping their instruments and eyes on this space rock to learn more about it, as well as learning more about the early solar system. Even at closest approach, 4179 Toutatis was 7 million km away or 18 times farther than the Moon. But that is close enough for radar imaging by NASA’s Goldstone Observatory, which has recently upgraded to a new digital imaging system, as well as optical imaging by other astronomers. Already, there are some preliminary findings from this 4.5-kilometer- long (3-mile-long) asteroid’s flyby.

“Toutatis appears to have a complicated internal structure,” said radar team member Michael Busch of the National Radio Astronomy Observatory. “Our radar measurements are consistent with the asteroid’s little lobe being ~15% denser than the big lobe; and they indicate 20% to 30% over-dense cores inside the two lobes.”

NASA says this raises the interesting possibility that asteroid Toutatis is actually a mash up of smaller space rocks. “Toutatis could be re-accumulated debris from an asteroid-asteroid collision in the main belt,” Busch said. The new observations will help test this idea.

Here are more images and video from Toutastis’ pass:

Adam Block from the Mount Lemmon SkyCenter/University of Arizona captured this footage:

Toutatis from Adam Block on Vimeo.

Astronomers are getting to know this asteroid, as it passes by Earth’s orbit every 4 years. It is one of the largest known potentially hazardous asteroids (PHAs), and its orbit is inclined less than half-a-degree from Earth’s. No other kilometer-sized PHA moves around the Sun in an orbit so nearly coplanar with our own. This makes it an important target for radar studies.

The team from the Remanzacco Observatory took this 120-second image of Toutatis:

Image from the ITelescope network (Nerpio, Spain) on 2012, Dec. 11.9, through a 0.15-m f/7.3 refractor + CCD. Credit: Ernesto Guido and Nick Howes/ Remanzacco Observatory.

And this was a fairly close pass for Toutatis: The next time Toutatis will approach at least this close to Earth is in November of 2069
when the asteroid will fly by at a distance of only 0.0198 AU (7.7 lunar distances).

NASA’s Goldstone radar in the Mojave Desert has been “pinging” the space rock every day starting on December 4, and will continue until the 22nd. The echoes highlight the asteroid’s topography and improve the precision with which researchers know the asteroid’s orbit.

Additionally, the Chinese Chang’e 2 spacecraft will be observing Toutatis tomorrow, on December 13, 2012 Chang’e 2 was originally launched to study the Moon but after completing its mission, Chang’e 2 departed from the L2 point in April 2012 to align itself to make a flyby of 4179 Toutatis, expected to take place at approximately 08:27 UTC on December 13.

“We already know that Toutatis will not hit Earth for hundreds of years,” said Lance Benner of NASA’s Near Earth Object Program.. “These new observations will allow us to predict the asteroid’s trajectory even farther into the future.”

4179 Toutatis - Close Approach , December 11, 2012, http://remanzacco.blogspot.it/

Animation from Ernesto Guido and Nick Howes of 40 consecutive 10-second exposures. Credit: Ernesto Guido and Nick Howes/ Remanzacco Observatory.

NASA says the asteroid is already remarkable for the way that it spins. Unlike planets and the vast majority of asteroids, which rotate in an orderly fashion around a single axis, Toutatis travels through space “tumbling like a badly thrown football,” as Benner describes it. One of the goals of the radar observations is to learn more about the asteroid’s peculiar spin state and how it changes in response to tidal forces from the Sun and Earth.

Here’s an animation of Asteroid Toutatis compiled the live broadcast from the Slooh space camera team:

Goldstone delay-Doppler radar images of Toutatis from December 11, 2012. Credit: NASA

Sources: NASA, Remanzacco Observatory, Chang’e 2 mission

Posted on by Nancy Atkinson

Two Asteroids Will Buzz Past Earth on December 11

Four computer generated views of Asteroid Toutatis based on Goldstone radar imagery. Via NASA

A newly discovered small asteroid named 2012 XE54 and a long-studied giant space rock named Toutatis will buzz past Earth during the next 24 hours, and astronomers are already watching the skies. While there is no danger of either hitting Earth, scientists have much to learn from both. Asteroid 2012 XE54 was discovered over the weekend on December 9 and it will safely pass between the Earth and the Moon’s orbit at a distance of about 226,000 km (141,000 miles) or about .6 lunar distances. Closest approach will be just a few hours after this article was posted, at 10:10 UTC on Dec. 11. But already an interesting event has already happened with this 28-meter-wide asteroid: it was eclipsed by Earth’s shadow. This is quite a rare event, and was visible to astronomers.

This animation shows the Sun and the Earth as observed from the asteroid 2012 XE54. If this eclipse occurs, the asteroid will be in Earth’s shadow. Animation via Pasquale Tricarico

Pasquale Tricarico of the Planetary Science Institute had predicted that the asteroid would pass through the Earth’s shadow, creating an asteroid eclipse, an event that is similar to an eclipse of the full Moon by Earth’s shadow. At 01:22 UTC on December 11 the eclipse began, and it left Earth’s shadow at 02:00 UTC. Those watching the asteroid noted that the asteroid “disappeared” from its track, and then reappeared after leaving Earth’s shadow.

“In two images taken at 01:30:16 and 01:31:18, 60sec exposure, 2012 XE54 appeared as a very faint and long track, then… nothing. In the following images there is no visible track. Wonderful!” wrote Elia Cozzi from the New Millennium Observatory, posting in the mpml asteroid research group message board.

We hope to have images of the event when they become available.

4179 Toutatis, with a shape that has been described as a “malformed potato” will pass at a large distance of 6.9 million kilometers (4.3 million miles) away from Earth, or more than 18 times the distance from the Earth to the Moon.

It is a biggie, though at 4.46 kilometers (2.7 miles) long and 2.4 kilometers (1.5 miles) wide, and is considered a potentially hazardous asteroid because it makes repeated passes by the Earth, about every four years. In comparison, the asteroid that is thought to have destroyed the dinosaurs was approximately 10 km (6 miles) wide.

It’s closest pass will be covered by the Slooh Space Camera on Tuesday, December 11th, with several live shows on Slooh.com, free to the public, starting at 20:00 UTC (12 PM PST / 3 PM EST, find international times here — accompanied by real-time discussions with Slooh President, Patrick Paolucci, and Astronomy Magazine columnist, Bob Berman.

At its maximum brightness, Toutatis might be barely visible through binoculars, but should be very bright through Slooh telescopes at its being tracked.

“We will be tracking Asteroid Toutatis live from two observatory locations – Canary Islands, off the coast of Africa and Arizona,” said Patrick Paolucci, President at Slooh.

Astronomers are interested in this returning asteroid to try and figure out what the asteroid is made of. Also by refining a model of the asteroid’s rotation, they’ll get a better idea of its composition, thereby gaining a greater understanding of the early solar system.

Lance Benner from JPL said that this asteroid is tumbling slowly, but with a complex motion.

“It’s a very peculiar rotation state,” Benner said. “It rotates very slowly and it tumbles in a manner somewhat similar to the way a football tumbles if you screw up a long pass.”

Sources: Slooh, Earth-Sky blog, JPL Small Body database, Planetary Science Institute