LEISA observes Jupiter

Mar 16, 2007
LEISA observes Jupiter
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

On February 24, 2007, the LEISA (pronounced “Leesa”) infrared spectral imager in the New Horizons Ralph instrument observed giant Jupiter in 250 narrow spectral channels. At the time the spacecraft was 6 million kilometers (nearly 4 million miles) from Jupiter; at that range, the LEISA imager can resolve structures about 400 kilometers (250 miles) across.

That may seem large, mission scientists say, but Jupiter itself is more than 144,000 kilometers (89,000 miles) across. “The detail revealed in these images is simply stunning,” says Dr. Dennis Reuter, Ralph/LEISA project scientist and a New Horizons co-investigator from NASA’s Goddard Space Flight Center in Greenbelt, Md. “Our instrument is performing spectacularly well.”

LEISA observes in 250 infrared wavelengths, which range from 1.25 micrometers to 2.50 micrometers. The three images shown above from that dataset are at wavelengths of 1.27 micrometers (left), 1.53 micrometers (center) and 1.88 micrometers (right).

The bright areas in the image frames are caused by solar radiation reflected from clouds and hazes in Jupiter’s atmosphere. Dark areas correspond to atmospheric regions where solar radiation is absorbed before it can be reflected. The dark circular feature in the upper left of all three images is the shadow of Jupiter’s innermost large moon, Io.

Light at 1.53 um (center frame) comes from relatively high in the atmosphere. The other two channels probe deeper atmospheric levels. Features that are bright in all three pictures come from high-altitude clouds. Features that are bright in the 1.27 and 1.88 um channels, but darker in the 1.53-um channel come from lower clouds. For example, there is an isolated circular feature (the “Little Red Spot”) in the lower left of the 1.53-um image. In the 1.27 and 1.88 um data, this circular feature is surrounded by other structures. The implication is that the “Little Red Spot” is caused by a system that extends far up into the atmosphere, while other structures are lower.

“The three frames shown here are just a sampling of what LEISA returned in this dataset,” says Dr. Don Jennings, LEISA principal investigator and a New Horizons co-investigator from NASA Goddard. “Combining data from all 250 channels will allow us to make detailed three-dimensional maps of the composition and circulation of the Jovian atmosphere.”

At closest approach to Jupiter on February 28, at a distance of about 2.5 million kilometers (1.4 million miles), LEISA’s resolution was about three times better than it was on February 24. LEISA images made at that far-better resolution are still stored in the spacecraft’s data recorder, awaiting downlink from New Horizons.

Source: Johns Hopkins Applied Physics Lab

Explore further: Astronomers release most detailed catalogue ever made of the visible Milky Way

add to favorites email to friend print save as pdf

Related Stories

US judge fines HP $59 mn for bribing Russian officials

6 hours ago

A judge on Thursday ordered US computer giant Hewlett-Packard to pay $58.8 million for bribing Russian government officials to win a big-money contract with the prosecutor general's office in that nation.

Solar storm heads Earth's way after double sun blasts

6 hours ago

Two big explosions on the surface of the sun will cause a moderate to strong geomagnetic storm on Earth in the coming days, possibly disrupting radio and satellite communications, scientists said Thursday.

US threatened Yahoo with huge fine over surveillance

7 hours ago

US authorities threatened to fine Yahoo $250,000 a day if it failed to comply with a secret surveillance program requiring it to hand over user data in the name of national security, court documents showed ...

Microbes evolve faster than ocean can disperse them

7 hours ago

Two Northeastern University researchers and their international colleagues have created an advanced model aimed at exploring the role of neutral evolution in the biogeographic distribution of ocean microbes.

Recommended for you

The entropy of black holes

Sep 12, 2014

Yesterday I talked about black hole thermodynamics, specifically how you can write the laws of thermodynamics as laws about black holes. Central to the idea of thermodynamics is the property of entropy, which c ...

Modified theory of dark matter

Sep 12, 2014

Dark matter is an aspect of the universe we still don't fully understand. We have lots of evidence pointing to its existence (as I outlined in a series of posts a while back), and the best evidence we have point ...

Gaia discovers its first supernova

Sep 12, 2014

(Phys.org) —While scanning the sky to measure the positions and movements of stars in our Galaxy, Gaia has discovered its first stellar explosion in another galaxy far, far away.

User comments : 0