Elara, moon of Jupiter, discovered 1905

Elara, the 8th largest moon of Jupiter, was discovered by Charles Dillon Perrine January 5, 1905.  He made his discovery at the Lick Observatory at the University of California on Mount Hamilton, east of San Jose.

Up until 1975, Elara was known as Jupiter VII when it was given the name Elara.  In Greek mythology, Elara is a lover of Zeus (Jupiter in Roman mythology).  Zeus hid her from his jealous wife Hera by putting her deep into the Earth, where she gave birth to the giant Tityos.

NASA lists Elara on their website as having a diameter of 43 km, but a 2015 article in the Astrophysical Journal lists its diameter as around 80 km.  Don't know when that will be resolved.  Elara orbits Jupiter every 258 days.

The New Horizons spacecraft captured several images of Elara as it passed on its way to Pluto. 

New Horizons spacecraft will flyby Ultima Thule New Year's Day 2019

The little spacecraft that could (and is still going strong), New Horizons will make a flyby of Kuiper Belt Object (KBO) 2014 MU69, nicknamed Ultima Thule on January 1, 2019.  It will be the farthest celestial body ever visited by a spacecraft. 

New Horizons made an historic flyby of Pluto in July 2015 and NASA was searching for a KBO suitable for it to study.  Ultima Thule was discovered using the Hubble Telescope in 2014 and chosen to be the next target. 

Ultima Thule is an irregular shaped object, being two smaller bodies orbiting each other at close range, or a contact binary system (two bodies joined together).  It will take 6 hours for signals to reach Earth from New Horizons.

First images of Kuiper Belt objects taken by New Horizons

New Horizons spacecraft, which made a flyby of Pluto in July 2015, took images of two Kuiper Belt objects, the farthest images from Earth ever captured by a spacecraft. 

These are falso-color images of 2012 HZ84 and 2012 HE85 are the closest-ever pictures of Kuiper Belt objects.

New Horizons is the fifth spacecraft to travel beyond the solar system at about 700,000 miles a day.  It made a course correction back in December to set it on its way to visit dwarf planet MU69 on January 1, 2019. 

NASA releases video of New Horizons Flyover of Pluto and Charon

Is this cool or what?  NASA scientists have created videos of Pluto and its moon Charon from the data received from the New Horizons spacecraft from its flyby two years ago.

Check these out!

New Horizons launched toward Pluto 2006

The New Horizons spacecraft, launched January 19, 2006, performed the first flyby of Pluto, exceeding everyone's expectations.  New Horizons reached Pluto (now 'dwarf planet') in July 2015 and sent back gigabytes of data which NASA scientists will be studying for years.

New Horizons took pictures of Pluto's surface as well as its moons, giving us a much better understanding of Charon.

Buoyed on the success of the mission, the New Horizons team requested and has been granted an extension.  New Horizons is headed toward 2014 MU69, a large body in the Kuiper Belt, arriving in 2019.  It will study other trans-Neptunian objects as well.

New Horizons spacecraft flies by Pluto a year ago

One year ago today, the New Horizons spacecraft made its closest approach to Pluto and its moon Charon.  Since then, NASA scientists have made numerous discoveries about the now-dwarf planet, such as craters, mountains and seas of solid nitrogen.

Last month, scientists discovered super-grand canyon on Charon that makes Arizona's Grand Canyon look like a scratch!







http://www.nasa.gov/feature/a-super-grand-canyon-on-pluto-s-moon-charon

Hydra, Pluto's Ice Moon

NASA reports that it has received the first compositional data on Pluto's four small moons from the New Horizons spacecraft.  They outermost satellite, Hydra, is covered mostly in unspoiled water ice.  Pluto's largest moon Charon is also covered mainly in water ice, but spectral analysis suggests that ice particles on Hydra are larger. NASA has described Hydra, only 31 miles long, as resembling the state of Michigan.  I suppose if you squint real hard...  This image was taken at a distance of 150,000 miles but closer pictures might not be forthcoming.  The New Horizons team is looking forward to obtaining data about Pluto's other moons.

http://www.nasa.gov/feature/pluto-s-icy-moon-hydra

http://www.nasa.gov/image-feature/new-horizons-captures-two-of-plutos-smaller-moons

Pluto's North Pole

The north polar region of Pluto, informally named Lowell Regio (for Percival Lowell), has long canyons that run vertically through this area.  In the image below, the widest canyon is about 45 miles across, with the actual North Pole indicated on the map.

The areas in red show pits where subsurface ice may have melted or sublimated from below, collapsing the ground above. 

The lines in blue and pink show winding valleys.  This image was taken by the New Horizons spacecraft from about 21,100 miles from the surface on July 14, 2015.

http://www.nasa.gov/feature/the-frozen-canyons-of-pluto-s-north-pole

Pluto has floating hills

The vast plain, informally named Sputnik Planum within Pluto’s ‘heart' is host to a mysterious phenomenon of 'floating' hills.  Images from Pluto suggest that the mountains are composed of water ice floating on denser nitrogen-dominated ice and move like icebergs in the Atlantic Ocean.

As they flow along convection movements, they accumulate in a feature informally named Challenger Colles – honoring the crew of the lost space shuttle.

http://www.nasa.gov/feature/pluto-s-mysterious-floating-hills

Kerberos, last of Pluto's moons

Data downloaded from New Horizons earlier this week shows a fuzzy image  of Pluto's moon, Kerberos.  It shows the moon is double-lobed shape, with the larger lobe approximately 5 miles (8 kilometers) across and the smaller lobe approximately 3 miles (5 kilometers) across.  This makes it the second smallest moon, after Styx.

Scientists previously thought Kerberos was much larger and its surface darker when it was discovered back in 2011.  Its surface is highly reflective, like Pluto's, which could mean it is covered with a layer of water ice.

A  family portrait of Pluto's moons:  Charon is by far the largest of the five.


http://www.nasa.gov/image-feature/plutos-tiny-moon-Kerberos

Picking up Styx

Last week, NASA released pictures of Styx, the smallest and faintest of Pluto's five moons.  The moon is only about 4.5 miles long and 3 miles across.  Its brightness suggests a highly reflective, icy surface similar to ones found on Nix and Hydra, two other moons.  The powerful Long Range Reconnaissance Imager (LORRI) camera was 391,000 miles away when it took photos but at that distance, it was difficult to detect details on Styx's surface. 

Blue skies and ice on Pluto

 

This dwarf planet on the edge of our solar system keeps offering surprises almost on a daily basis.  NASA reported today that the New Horizons spacecraft has found numerous, small exposed regions of water ice on the surface of Pluto.  Data collected from the Ralph spectral composition mapper, an imager to map surface compositions and temperatures, made the discovery, but only in certain areas.  Exposed ice does not appear in larger expanses, which could mean it is covered or masked by more volatile ices.

Other images sent from New Horizons show blue atmospheric hazes.  Although the particles causing the hazes are probably gray or red, they scatter blue light that indicates the size and composition of the particles.  Scientists theorize tholins in the atmosphere are the cause.

The term ‘tholin’ was coined by Carl Sagan and Bishun Khare in 1979.  In their laboratory, they produced complex organic solids from “cosmically abundant” gases, such as methane, ethane, ammonia and water.  Sagan and Khare say these particles are relevant to the origin of life.

This process was observed in the upper atmosphere of Titan, Saturn’s moon, where UV light ionizes nitrogen and methane molecules.  They react with each other to form more and more complex ions.  This ionizing and recombining results in large molecules that become small particles.  Volatile gases condense on their surfaces and coat them with ice frost before they fall to the planet’s surface, giving Pluto a red color.