Shooting past Pluto
The New Horizons spacecraft took 9 years to reach Pluto. But on July 14th, it will blast by Pluto in just one hour. It can't slow down!
In fact, it's the fastest human-made object ever to be launched from Earth. When it took off from Cape Canaveral in January 2006, it was moving faster than escape velocity, not just for the Earth
, but for the Solar System!
It was moving at 58,000 kilometers per hour.
When it passed Jupiter it got pulled by that huge planet's gravity and fired out at 83,000 kilometers per hour. As it climbed up out of the Solar System it slowed down. But when it reaches Pluto, it will still be going almost 50,000 kilometers per hour.
That's fast enough that even a speck of dust could be fatal. Luckily, Pluto doesn't seem to have rings.
It will punch through the plane that Pluto's moons orbit, and collect so much data that it will take months
for it all to be sent back to Earth.
And as it goes behind Pluto, it will see a carefully timed radio signal sent from the Deep Space Network
here on Earth: 3 deep-space communication facilities located in California, Spain and Australia.
This signal has to be timed right, since it takes about 4 hours for radio waves - or any other form of light - to reach Pluto. The signal will be blocked when Pluto gets in the way, and the New Horizons spacecraft can use this to learn more about Pluto's exact diameter, and more.
Then: out to the Kuiper belt, where the cubewanos, plutinos and twotinos live...
You can see a timeline of the flyby here:http://blogs.scientificamerican.com/life-unbounded/the-pluto-punch-through/
On July 14, 2015 at 11:49:57 UTC, New Horizons will make its closest approach to Pluto. It will have a relative velocity of 13.78 km/s (49,600 kilometers per hour), and it will come within 12,500 kilometers from the planet's surface.
At 12:03:50, it will make its closest approach to Pluto's largest moon, Charon.
At 12:51:25, Pluto will occult the Sun - that is, come between the Sun and the New Horizons spacecraft.
At 12:52:27, Pluto will occult the Earth. This is only important because it means the radio signal sent from the Deep Space Network will be blocked.
Starting 3.2 days before the closest approach, New Horizons will map Pluto and Charon to 40 kilometer resolution. This is enough time to image all sides of both bodies. Coverage will repeat twice per day, to search for changes due to snows or cryovolcanism. Still, due to Pluto's tilt, a portion of the northern hemisphere will be in shadow at all times. The Long Range Reconnaissance Imager (LORRI
) should be able to obtain select images with resolution as high as 50 meters/pixel, and the Multispectral Visible Imaging Camera (MVIC
) should get 4-color global dayside maps at 1.6 kilometer resolution. LORRI and MVIC will attempt to overlap their respective coverage areas to form stereo pairs.
The Linear Etalon Imaging Spectral Array (LEISA
) will try to get near-infrared maps at 7 kilometers per pixel globally and 0.6 km/pixel for selected areas. Meanwhile, the ultraviolet spectrometer Alice
will study the atmosphere, both by emissions of atmospheric molecules (airglow), and by dimming of background stars as they pass behind Pluto.
Other instruments will will sample the high atmosphere, measure its effects on the solar wind, and search for dust - possible signs of invisible rings of Pluto. The communications dish will detect the disappearance and reappearance of the radio signal from the Deep Space Network, measuring Pluto's diameter and atmospheric density and composition.
The first highly compressed images will be transmitted within days. Uncompressed images will take as long as nine months to transmit, depending on how much traffic the Deep Space Network is experiencing.
Most of this last information is from:https://en.wikipedia.org/wiki/New_Horizons
The picture is from here:http://www.astronomy.com/magazine/ask-astro/2014/01/new-horizons #astronomy