Universe Today
Countdown to discovery! Not since Voyager 2's
in 1989 have we flung a probe into the frozen outskirts of the Solar System. Speeding along at 30,800 miles per hour
will pierce the Pluto system like a smartly aimed arrow.
[caption id="attachment_121333" align="aligncenter" width="580"]
Newest view of Pluto seen from New Horizons on July 11, 2015 shows a world that continues to grow more fascinating and look stranger every day. See annotated version below.
Credits: NASA/JHUAPL/SWRI[/caption]
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For the first time on Pluto, this view reveals linear features that may be cliffs, as well as a circular feature that could be an impact crater. Rotating into view is the bright heart-shaped feature that will be seen in more detail during New Horizons' closest approach on July 14. The annotated version includes a diagram indicating Pluto's north pole, equator, and central meridian.
Credits: NASA/JHUAPL/SWRI[/caption]
Edging within 7,800 miles of its surface at 7:49 a.m. EDT, the spacecraft's long-range telescopic camera will resolve features as small as 230 feet (70 meters). Fourteen minutes later, it will zip within 17,930 miles of Charon as well as image Pluto's four smaller satellites — Hydra, Styx, Nix and Kerberos.
[caption id="attachment_121321" align="aligncenter" width="580"]
This image shows New Horizons' current position (3 p.m. EDT July 12) along its planned Pluto flyby trajectory. The green segment of the line shows where New Horizons has traveled; the red indicates the spacecraft's future path. The Pluto system is tilted on end because the planet's axis is tipped 123° to the plane of its orbit. Credit: NASA/JHUAPL/SWRI[/caption]
After zooming past, the craft will turn to photograph Pluto eclipsing the Sun as it looks for the faint glow of rings or dust sheets illuminated by backlight. At the same time, sunlight reflecting off Charon will faintly illuminate Pluto's backside. What could be more romantic than Charonshine?
Six other science instruments
will build thermal maps of the Pluto-Charon pair, measure the composition of the surface and atmosphere and observe Pluto's interaction with the solar wind. All of this will happen autopilot. It has to. There's just no time to send a change instructions because of the nearly 9-hour lag in round-trip communications between Earth and probe.
[caption id="attachment_121322" align="aligncenter" width="580"]
Instruments New Horizons will use to characterize Pluto are REX (atmospheric composition and temperature); PEPSSI (composition of plasma escaping Pluto's atmosphere); SWAP (solar wind studies); LORRI (close up camera for mapping, geological data); Star Dust Counter (student experiment measuring space dust during the voyage); Ralph (visible and IR imager/spectrometer for surface composition and thermal maps) and Alice (composition of atmosphere and search for atmosphere around Charon). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute[/caption]
Want to go along for the ride? Download and install NASA's interactive app
and then click the launch button on the website. You'll be shown several options including a
live view
and
preview
. Click preview and sit back to watch the next few days of the mission unfold before your eyes.
[caption id="attachment_121325" align="aligncenter" width="580"]
American astronomer Clyde Tombaugh discovered Pluto in 1930 from Lowell Observatory. Tombaugh died in 1997, but an ounce of his ashes, affixed to the spacecraft in a 2-inch aluminum container. "Interned herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and the solar system's 'third zone.' Adelle and Muron's boy, Patricia's husband, Annette and Alden's father, astronomer, teacher, punster, and friend: Clyde Tombaugh (1906-1997)"[/caption]
Like me, you've probably wondered how daylight on Pluto compares to that on Earth. From 3 billion miles away, the Sun's too small to see as a disk with the naked eye but still wildly bright. With NASA's
, select your city on an
and get the time of day when the two are equal. For my city, daylight on Pluto equals the gentle light of early evening twilight six minutes after sunset. An ideal time for walking, but step lightly. In Pluto's gentle gravity, you only weigh 1/15 as much as on Earth.
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Pluto and its inclined orbit are highlighted among the hundreds of thousands of icy asteroids in the Kuiper Belt beyond Neptune. Credit: NASA[/caption]
New Horizons is the first mission to the
, a gigantic zone of icy bodies and mysterious small objects orbiting beyond Neptune. This region also is known as the "third" zone of our solar system, beyond the inner rocky planets and outer gas giants. Pluto is its most famous member, though not necessarily the largest.
, first observed in 2003, is nearly identical in size. It's estimated there are hundreds of thousands of icy asteroids larger than 61 miles (100 km) across along with a
trillion
comets in the Belt, which begins at 30 a.u. (30 times Earth's distance from the Sun) and reaches to 55 a.u.
[caption id="attachment_121329" align="aligncenter" width="580"]
During its fleeting flyby, New Horizons will slice across the Pluto system, turning this way and that to photograph and gather data on everything it can. Crucial occultations are shown that will be used to determine the structure and composition of Pluto's (and possibly Charon's) atmosphere. Sunlight reflected from Charon will also faintly illuminate Pluto's backside. Credit: NASA with additions by the author[/caption]
Below you'll find a schedule of events in Eastern Time. (Subtract one hour for Central, 2 hours for Mountain and 3 hours for Pacific). Keep in mind the probe will be busy shooting photos and gathering data during the flyby, so we'll have to wait until Wednesday July 15 to see the the detailed close ups of Pluto and its moons. Even then, New Horizons' recorders will be so jammed with data and images, it'll take months to beam it all back to Earth.
[caption id="attachment_121336" align="aligncenter" width="580"]
A new photo of Charon, too! Chasms, craters, and a dark north polar region are revealed in this image of Pluto's largest moon taken by New Horizons on July 11, 2015. The annotated version includes a diagram showing Charon's north pole, equator, and central meridian, with the features highlighted. The prominent crater is about 60 miles (96 km) across; the chasms appear to be geological faults.
Credits: NASA/JHUAPL/SWRI[/caption]
Fasten your seat belts — we're in for an exciting ride.
We'll be reporting on results and sharing photos from the flyby here at Universe Today, but you'll also want to check out NASA's live coverage on
its
and
.
Monday, July 13
10:30 a.m. to noon – Media briefing on mission status and what to expect broadcast live on
Tuesday, July 14
7:30 to 8 a.m. – Arrival at Pluto! Countdown program on
At approximately 7:49 a.m., New Horizons is scheduled to be as close as the spacecraft will get to Pluto, approximately 7,800 miles (12,500 km) above the surface, after a journey of more than 9 years and 3 billion miles. For much of the day, New Horizons will be out of communication with mission control as it gathers data about Pluto and its moons.
The moment of closest approach will be marked during a live
broadcast that includes a countdown and discussion of what's expected next as New Horizons makes its way past Pluto and potentially dangerous debris.
8 to 9 a.m. – Media briefing, image release on
Wednesday, July 15
3 to 4 p.m. – Media Briefing: Seeing Pluto in a New Light; live on
and release of close-up images of Pluto's surface and moons, along with initial science team reactions.
We'll have the latest Pluto photos for you, but you can also check these excellent sites:
*
Long Range Reconnaissance Imager (LORRI) archive
*
*
New Horizons science photo gallery
Need more Pluto? Spend a few minutes watching this excellent New York Times
.