NASA's Lucy Spacecraft Spots Jupiter's Trojan Asteroids For the First Time

A NASA probe sent to observe Jupiter's swarm of asteroids recently caught the first glimpse of its rocky targets, capturing deep-space images of four of the mysterious Trojans. Gizmodo reports: The Lucy spacecraft used its highest resolution imager, L'LORRI (Lucy LOng Range Reconnaissance Imager), to photograph four Trojan asteroids during a two-day period from March 25 to 27, NASA announced on Thursday. The first asteroids to be seen by Lucy are: Eurybates, Polymele, Leucus, and Orus. Those four are part of two large groups of rocky bodies that lead and follow Jupiter as it orbits the Sun. Lucy is still a long way from reaching its asteroid targets, which are currently about 330 million miles (530 million kilometers) away from the probe. That's more than three times the average distance between Earth and the Sun, according to NASA.

The initial set of images are the first in a series of observations to measure how the Trojan asteroids reflect light when seen from a higher angle than ground-based observations, according to NASA. The images will then help NASA decide on exposure times to use for Lucy's close-up observations of the asteroids.

Lucy in the sky with diamonds

[backslashdot]

There, got that out of the way. Also, I'm glad Jupiter's finally using a condom. We don't need more asteroids.

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[Anonymous Coward]

They're called Trojan asteroids, probably means it failed.

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[Mal-2]

They're called Trojan asteroids because Jupiter took off the condom and shook the fuck out of it.

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[Virtucon]

Man if it's dry then it was on way too long.

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[Mal-2]

Space is a hell of a place.

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[RockDoctor]

Not quite sure where the condom reference comes from, but if there's an analogy to how Jupiter "gets" asteroid "companions" is somewhere closer to "adoption" (or maybe forcible kidnapping) than actual reproduction.

It's not as if there's a magical mystery "asteroid factory" somewhere out there.

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[RockDoctor]

Ah. Never needed to buy a condom in America. She spat.

I somewhat wonder how the advertising dudes got from "rubber dick cap" to the image of the losers of one of the first wars on record - who would have gotten really fucked, but with a sword with no condom on it.

Quoth Marvin : it gives me a headache to think down to that level.

Lucy in the sky with diamonds?

[nospam007]

Or just solar panels?

Necessary caveats are necessary

[Entrope]

That's more than three times the average distance between Earth and the Sun, according to NASA.

I am glad that the writer clarified that the only reason they know that is because NASA said so, not because they know the Earth orbits roughly 93 million miles from the Sun, and can do the maths to determine that 330 > 3 * 93.

L'LORRI

[necro81]

Space missions have long been known as a place where abstruse and strained acronyms are born. However, for anyone wondering where the name "L'LORRI" comes from: the New Horizon's main camera was a device called LORRI [wikipedia.org]. (Given what the acronym stands for, it should probably be LoRRI, but I guess people are lazy with the Shift key.) This was the camera that gave us such awesome images of Pluto [google.com]. The Lucy mission is using essentially a copy of that device, so they just tacked another letter on. But since LLORRI looks weird to English speakers, they decided to break it up by throwing in an unnecessary apostrophe.

Perfectly obvious, right?

L'LORRI a pretty sweet piece of work, too. It is not merely a camera, but more like a decent Newtonian reflector telescope [wikipedia.org] that happens to have a CCD at one end. It's main mirror is ~200 mm diameter and made of silicon carbide. The housings are made of magnesium with a light-absorbing dark coating. The image sensor is only 1024x1024 pixels, but because it is over 13 mm square, the pixels are enormous compared to what's inside a full-frame DSLR, and so it has a much higher sensitivity and dynamic range.

On the New Horizons mission, the whole camera was rigidly mounted to the spacecraft bus, so pointing it required pointing the whole spacecraft. For Lucy, it's mounted on an instrument platform that can be pointed independently from the rest of the spacecraft, which will allow for steadier positioning and less motion blur during long exposures.

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[Virtucon]

My new design is called LLLLORRI ludicrously lavish luxurious long-range reconnaissance Imager. It'll be yellow and will have curved edges.

Fuck it, just call it the expensive, hi-res camera.

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[RockDoctor]

the expensive, hi-res camera.

... on a precision driven mounting. Which may well be more expensive (by weight, cost, computation, or all) than the optics.

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[RockDoctor]

Space missions have long been known as a place where abstruse and strained acronyms are born.

Some years ago - back in the Dark Ages before COVID - someone published a program that would take a list of keywords (say, your work-specific spelling checker "accept this spelling, stupid machine!" list) and churn out lots of possible, and really strained, acronyms.

It's science - why use creativity where you can (at least partly) automate it?

For Lucy, it's mounted on an instrument platform that can be pointed ind

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[necro81]

Which also means, at least three angular measurement devices (one for each axis) and another level of software to get the target's position on the sky from the spacecraft's orientation.

True, but this is nothing new. The Voyager probes had a scanning platform, for instance.

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[RockDoctor]

Yep. And pretty much everything from Apollo to New Horizons has experienced software problems for which one of the causes has been the computational load. So it remains something that one has to keep an eye on.