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Astronomers were watching when comet P/2016 BA14 flew past Earth on March 22. At the time of its closest approach, the comet was about 2.2 million miles (3.5 million kilometers) away, making it the third closest comet flyby in recorded history (see "A 'Tail' of Two Comets"). Radar images from the flyby indicate that the comet is about 3,000 feet (1 kilometer) in diameter.

By NASA 3-24-16

The scientists used the Goldstone Solar System Radar in California's Mojave Desert to track the comet. "We were able to obtain very detailed radar images of the comet nucleus over three nights around the time of closest approach," said Shantanu Naidu, a postdoctoral researcher at NASA's Jet Propulsion Laboratory in Pasadena, California, who works with the radar team and led the observations during the comet's flyby. "We can see surface features as small as 8 meters per pixel.

"The radar images show that the comet has an irregular shape: looks like a brick on one side and a pear on the other," Naidu said. "We can see quite a few signatures related to topographic features such as large flat regions, small concavities and ridges on the surface of the nucleus. "

According to the new radar observations, comet P/2016 BA14 appears to spin around its axis once every 35 to 40 hours.

Vishnu Reddy, of the Planetary Science Institute, Tucson, Arizona, also observed comet P/2016 BA14 using the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. Data collected (infrared spectra) indicate that the comet reflects less than 3 percent of the sunlight that falls on its surface. Comet nuclei are as dark as fresh asphalt. However, infrared spectra can often yield clues to the makeup of these primitive denizens of the solar system. [...]
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     [...]

During the upcoming March 5 flyby, asteroid 2013 TX68 could fly past Earth as far out as 9 million miles (14 million kilometers) or as close as 11,000 miles (17,000 kilometers). The variation in possible closest approach distances is due to the wide range of possible trajectories for this object, since it was tracked for only a short time after discovery.

Scientists at NASA's Center for NEO Studies (CNEOS) at the Jet Propulsion Laboratory in Pasadena, California, have determined there is no possibility that this object could impact Earth during the flyby next month. But they have identified an extremely remote chance that this small asteroid could impact on Sep. 28, 2017, with odds of no more than 1-in-250-million. Flybys in 2046 and 2097 have an even lower probability of impact.

"The possibilities of collision on any of the three future flyby dates are far too small to be of any real concern," said Paul Chodas, manager of CNEOS. "I fully expect any future observations to reduce the probability even more."

Asteroid 2013 TX68 is estimated to be about 100 feet (30 meters) in diameter. By comparison, the asteroid that broke up in the atmosphere over Chelyabinsk, Russia, three years ago was approximately 65 feet (20 meters) wide. If an asteroid the size of 2013 TX68 were to enter Earth's atmosphere, it would likely produce an air burst with about twice the energy of the Chelyabinsk event.

The asteroid was discovered by the NASA-funded Catalina Sky Survey on Oct. 6, 2013, as it approached Earth on the nighttime side. After three days of tracking, the asteroid passed into the daytime sky and could no longer be observed. Because it was not tracked for very long, scientists cannot predict its precise orbit around the sun, but they do know that it cannot impact Earth during its flyby next month. [...]
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      The data NASA's New Horizons spacecraft collects during its historic flyby of Pluto today (July 14) may reveal insights into not only the dwarf planet, but also Saturn's huge moon Titan, scientists say.

With its nitrogen and methane atmosphere, Pluto bears a strong resemblance to Titan — one of the most potentially habitable bodies in the solar system — or at least how Titan may have been in the past.

"New Horizons will help us confirm our photochemical understanding [of] Pluto. Since the photochemistry is similar to Titan, it will help us understand the processes there, too," said Michael Wong, a graduate student at the California Institute of Technology in Pasadena who worked with Yuk Yung, also of Caltech, and Randy Gladstone, of the Southwest Research Institute in Colorado, to study the possibilities of a frozen Titan. . . .
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      NASA’s New Horizons spacecraft is at Pluto.

After a decade-long journey through our solar system, New Horizons made its closest approach to Pluto Tuesday, about 7,750 miles above the surface -- roughly the same distance from New York to Mumbai, India – making it the first-ever space mission to explore a world so far from Earth.

Members of the New Horizons science team react to seeing the spacecraft's last and sharpest image of Pluto before closest approach later in the day, Tuesday, July 14, 2015 at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. Credits: NASA/Bill Ingalls

“I’m delighted at this latest accomplishment by NASA, another first that demonstrates once again how the United States leads the world in space,” said John Holdren, assistant to the President for Science and Technology and director of the White House Office of Science and Technology Policy. “New Horizons is the latest in a long line of scientific accomplishments at NASA, including multiple missions orbiting and exploring the surface of Mars in advance of human visits still to come; the remarkable Kepler mission to identify Earth-like planets around stars other than our own; and the DSCOVR satellite that soon will be beaming back images of the whole Earth in near real-time from a vantage point a million miles away. As New Horizons completes its flyby of Pluto and continues deeper into the Kuiper Belt, NASA's multifaceted journey of discovery continues."

“The exploration of Pluto and its moons by New Horizons represents the capstone event to 50 years of planetary exploration by NASA and the United States," said NASA Administrator Charles Bolden. “Once again we have achieved a historic first. The United States is the first nation to reach Pluto, and with this mission has completed the initial survey of our solar system, a remarkable accomplishment that no other nation can match.”

Per the plan, the spacecraft currently is in data-gathering mode and not in contact with flight controllers at the Johns Hopkins University Applied Physical Laboratory (APL) in Laurel, Maryland. Scientists are waiting to find out whether New Horizons “phones home,” transmitting to Earth a series of status updates that indicate the spacecraft survived the flyby and is in good health. The “call” is expected shortly after 9 p.m. tonight.

The Pluto story began only a generation ago when young Clyde Tombaugh was tasked to look for Planet X, theorized to exist beyond the orbit of Neptune. He discovered a faint point of light that we now see as a complex and fascinating world.

"Pluto was discovered just 85 years ago by a farmer's son from Kansas, inspired by a visionary from Boston, using a telescope in Flagstaff, Arizona,” said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington. "Today, science takes a great leap observing the Pluto system up close and flying into a new frontier that will help us better understand the origins of the solar system.”

New Horizons’ flyby of the dwarf planet and its five known moons is providing an up-close introduction to the solar system's Kuiper Belt, an outer region populated by icy objects ranging in size from boulders to dwarf planets. Kuiper Belt objects, such as Pluto, preserve evidence about the early formation of the solar system.

New Horizons principal investigator Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado, says the mission now is writing the textbook on Pluto.

"The New Horizons team is proud to have accomplished the first exploration of the Pluto system,” Stern said. “This mission has inspired people across the world with the excitement of exploration and what humankind can achieve.”

New Horizons’ almost 10-year, three-billion-mile journey to closest approach at Pluto took about one minute less than predicted when the craft was launched in January 2006. The spacecraft threaded the needle through a 36-by-57 mile (60 by 90 kilometers) window in space -- the equivalent of a commercial airliner arriving no more off target than the width of a tennis ball.

Because New Horizons is the fastest spacecraft ever launched – hurtling through the Pluto system at more than 30,000 mph, a collision with a particle as small as a grain of rice could incapacitate the spacecraft. Once it reestablishes contact Tuesday night, it will take 16 months for New Horizons to send its cache of data – 10 years’ worth -- back to Earth.

New Horizons is the latest in a long line of scientific accomplishments at NASA, including multiple rovers exploring the surface of Mars, the Cassini spacecraft that has revolutionized our understanding of Saturn and the Hubble Space Telescope, which recently celebrated its 25th anniversary. All of this scientific research and discovery is helping to inform the agency’s plan to send American astronauts to Mars in the 2030’s.

“After nearly 15 years of planning, building, and flying the New Horizons spacecraft across the solar system, we’ve reached our goal,” said project manager Glen Fountain at APL “The bounty of what we’ve collected is about to unfold.”

APL designed, built and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the mission, science team, payload operations and encounter science planning. New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama.

Follow the New Horizons mission on Twitter and use the hashtag #PlutoFlyby to join the conversation. Live updates also will be available on the mission Facebook page.

For more information on the New Horizons mission, including fact sheets, schedules, video and images, visit:
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