Thursday January 24, 2019

NASA’s Ralph Will Explore Jupiter’s Trojan Asteroids In 2021

Ralph's infrared detectors are 2,000 pixels square, compared to New Horizons Ralph's 256 by 256, allowing for images with more detail.

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NASA, tissue
US shutdown delays space missions but NASA not grounded: Report,

 NASA’s Ralph, one of the most well-travelled scientific instrument, is set to explore Jupiter’s Trojan asteroids aboard the Lucy spacecraft in 2021, the US space agency said.

Ralph has made many discoveries since it first launched aboard the New Horizons spacecraft in 2006. Given a name and not an acronym, Ralph enables the study of the composition and atmospheres of celestial objects.

In 2021, the Lucy spacecraft will carry a near-twin of Ralph, called L’Ralph (“Lucy Ralph”), to investigate Jupiter’s Trojan asteroids, which are remnants from the early days of the solar system, NASA said in a statement on Wednesday.

jupiter
Jupiter. Pixabay

The L’Ralph instrument suite will study this diverse group of bodies. Lucy will fly by six Trojans and one Main Belt asteroid, more than any other previous asteroid mission.

L’Ralph will detect the Trojan asteroids’ chemical fingerprints, the statement said.

L’Ralph allows scientists to interpret data provided by the Sun’s reflected light that are the fingerprints of different elements and compounds.

These data could provide clues about how organic molecules form in primitive bodies, a process that might also have led to the emergence of life on Earth.

L’Ralph needs to have many capabilities in a small, light body structure to keep the spacecraft efficient and the mission productive.

NASA, Hubble, Keplar, asteroids
L’Ralph needs to have many capabilities in a small, light body structure to keep the spacecraft efficient and the mission productive.Flickr

Its instrument suite contains the Multi-spectral Visible Imaging Camera (MVIC) and the Linear Etalon Imaging Spectral Array (LEISA), both of which are fed by the same optics, meaning that Ralph can observe both visible and infrared wavelengths.

These dual capabilities are what makes Ralph and its cousin L’Ralph so special, according to Dennis Reuter, the instrument principal investigator for L’Ralph.

“Most instruments can image visible or infrared wavelengths, but L’Ralph can do both,” said Reuter.

Also Read: Mars Curiosity Rover Returns Back To Work: NASA

Compared to the Ralph that flies with New Horizons, Lucy’s L’Ralph has enhanced technology. It can detect a broader spectrum of electromagnetic radiation, it has a moving mirror that reflects light into L’Ralph instead of requiring movements of the entire spacecraft.

Ralph’s infrared detectors are 2,000 pixels square, compared to New Horizons Ralph’s 256 by 256, allowing for images with more detail. (IANS)

Next Story

Asteroids Are Falling On Earth’s Surface Twice As Often: Study

This enhanced impact rate poses a threat for the next mass extinction event.

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Asteroids
This Dec. 29, 1968, photo made available by NASA shows craters on the moon. For the past 290 million years, giant rocks from space have been crashing into Earth more than twice as often as they did in the previous 700 million years, according to a new study. VOA

Giant rocks from space are falling from the sky more than they used to, but don’t worry.

For the past 290 million years, large asteroids have been crashing into Earth more than twice as often as they did in the previous 700 million years, according to a new study in Thursday’s journal Science.

But no need to cast a wary glance up. Asteroids still only smack Earth on average every million or few million years, even with the increased crash rate. NASA’s list of potential big space rock crashes shows no pending major threats. The biggest known risk is a 4,200-foot (1.3-km) wide asteroid with a 99.988 percent chance that it will miss Earth when it whizzes very near here in 861 years.

Tell that to the dinosaurs. Most scientists think dinosaurs and a lot of other species went extinct after a huge space rock crashed into Central America about 65 million years ago.

Earth, Asteroids
Taurids meteor shower lights up the sky. The risk of asteroids hitting the Earth has grown over the years. Wikimedia

“It’s just a game of probabilities,” said study lead author Sara Mazrouei, a University of Toronto planetary scientist. “These events are still rare and far between that I’m not too worried about it.”

Mazrouei and colleagues in the United Kingdom and United States compiled a list of impact craters on Earth and the moon that were larger than 12 miles (20 km) wide and came up with the dates of them. It takes a space rock that’s half a mile (800 meters) wide to create holes that big.

The team counted 29 craters that were no older than 290 million years and nine between 291 million years and 650 million years old.

But we can see relatively few big craters on Earth because the planet is more than 70 percent ocean and past glaciers smoothed out some holes, said University of Toronto planetary scientist Rebecca Ghent, a study co-author.

Earth, Asteroids
These rocks were rare survivors from a very different time on Earth. Pixabay

Extrapolating for what can’t be seen brings the total to about 260 space crashes on Earth in the last 290 million years. Adding in other factors, the science team determined that the current space crash rate is 2.6 times more than the previous 700 million years.

Craters older than 650 million years are mostly wiped off on Earth by glacial forces so the scientists used impact craters on the nearby moon as a stand-in for holes between 650 million and 1 billion years old. The moon is a good guide for estimating Earth crashes, because it is close enough to be in the same bombardment path and its craters last longer.

Mixed reactions

So what happened nearly 300 million years ago?

“Perhaps an asteroid family was broken up in the asteroid belt,” Mazrouei speculated. The space rocks then headed toward the Earth and moon, and the planet got slightly more because it is a bigger target and it has higher gravity, Ghent said.

Oldest known asteroid family
An asteroid family. Wikimedia

Outside scientists are split about the research. Jay Melosh at Purdue said he found the number of craters too small to come to a reasonable conclusion, but Harvard’s Avi Loeb said the case was convincing.

Also Read: Newly Discovered Super-Earth Exoplanet May Sustain Primitive Life

Humans might not have emerged without mass extinctions from space rocks about 250 million and 65 million years ago, Loeb said in an email, adding, “but this enhanced impact rate poses a threat for the next mass extinction event, which we should watch for and attempt to avoid with the aid of technology.”

“This demonstrates how arbitrary and fragile human life is,” Loeb wrote. (VOA)