New Horizons approaches Pluto July 14
Pluto was in its final months as an official planet when NASA launched its New Horizons spacecraft on Jan. 19, 2006.
Debates about its demotion to dwarf planet have continued to rage during most of the nearly 10 years the first spacecraft to visit Pluto has spent hurtling toward its mysterious target.
New Horizons is finally scheduled to make its closest approach to Pluto on Tuesday, July 14, exactly three seconds before 7:50 a.m. Some ashes from Clyde Tombaugh, Pluto’s discoverer who died in 1997, are aboard.
To see Pluto from Earth, you would need a telescope with a 12-inch aperture (those retail for more than $2,500), and even then it would look like a nondescript star.
Getting 2.6 to 4.6 billion miles closer, though — depending on how far it is from Earth at that point in its highly elliptical orbit — Pluto is thought to have a mostly rock core encased in water ice with a surface of more than 98 percent nitrogen ice with traces of methane and carbon monoxide. The dwarf planet has a funky color, varying among black, dark orange and white.
Pluto’s diameter is about two-thirds that of our moon. The dwarf planet has five of its own moons. Charon, the largest and closest, reigned alone from its discovery in 1978 until two more, Nix and Hydra, were discovered in 2005. Kerberos came to light in 2011 followed by Styx in 2012.
New Horizons will mostly focus on Pluto and Charon, though. Scientific observations began in February when NASA released new images of Pluto taken at the end of January. Images from April show a possible polar ice cap on Pluto. Images shot between May 29 and June 19 show that the hemisphere on Pluto that New Horizons will fly over has the greatest variety of terrain types seen on the planet so far. They also show that Charon has a mysterious dark region that forms what appears to be the opposite of a polar ice cap.
The richest data yet, of course, is expected to be captured July 14 when New Horizons captures data from about 7,750 miles above Pluto’s surface, and then moves on to study another object in the Kuiper Belt.
Before it leaves Pluto behind completely, though, New Horizons will turn its camera around and search for any faint rings around Pluto and use sunlight reflected from Charon to take pictures of the section of Pluto’s surface that is now immersed in constant darkness.
After Pluto’s surface features are revealed, NASA plans to have a field day naming them.
So here’s what we can expect as of this writing: New Horizons will contact Earth at 9 p.m. Eastern time on July 14 to confirm all went well.
Several hours later, it will begin to transmit flyby images and other data before it downloads a complete but quite compressed “browse dataset” of the observations made during the flyby so that scientists can get a glimpse of the gold.
The first images that will make the topography look three-dimensional probably won’t be available until September, and transmitting the entire uncompressed dataset will take about 16 months.
Pluto may not be a planet, but soon it will no longer be a mystery.
July 16: New moon. This is the best time of the month to observe faint objects like galaxies and star clusters.
July 28, 29: Delta Aquarids meteor shower peaks. This is an average shower that can produce up to 20 meteors per hour at peak. It is produced by debris left behind by comets Marsden and Kracht burning up in our atmosphere as Earth passes through the debris streams. The shower runs annually from July 12 to Aug. 23, so any random shooting stars you may catch during this timeframe are likely from this shower. Light from the nearly full moon will unfortunately drown out all but the brightest meteors this year. Best views will be from a dark location after midnight. Meteors will radiate from the constellation Aquarius, but can appear anywhere in the sky.
July 31: Full moon.