The Extremely Large Telescope is currently under construction, with the most recent milestones including progress made with building the dome, central structure and the base for the primary mirror.
www.space.com
By
Samantha Mathewson Published 18 hours ago
Construction of the world's largest telescope moves forward with progress of the structure's dome and housing for the primary mirror.
The
European Southern Observatory's (ESO)
Extremely Large Telescope (ELT) —
the world's largest visible- and infrared-light telescope — is currently under development on the Cerro Armazones mountain in Chile's Atacama Desert. The mighty telescope is expected to see its "first light" by 2028, with the goal of observing terrestrial exoplanets and their atmospheres, as well as measuring the expansion of the universe.
New photos from the ESO reveal that progress has really been made with construction of the ELT, including its dome,
central structure and base of the M1 mirror — one of five mirrors that will work together to observe the cosmos.
The ELT "will be one of the main flagships of the European Southern Observatory for the next two decades," the ESO said in
a statement releasing the new images.
Once complete, the M1 mirror will measure 128 feet (39 meters) across and weigh a whopping 200 tons. The white lattice
structure shown in the center of the dome will hold the M1 mirror, allowing it to move smoothly during observations and compensate for varying gravity loads, wind conditions, vibrations, or changes in temperature.
On-site webcams, drone footage and photographs of the construction site allow for step-by-step progress updates of the ELT. In addition to the recent photos shared by the ESO, you can track development of the telescope through
interactive webcam footage that streams live 24/7. The observatory also shared a
time-lapse video of the construction site, with the warm glow of the sun rising over the optical telescope.
If all goes according to plan, the anticipated
development timeline for the ELT will see the telescope's secondary mirror (M2) completed in 2025. The 14-foot (4.25-meter) mirror — the largest convex mirror ever produced — will reflect light collected by M1 to the 12-foot (3.75-meter) tertiary mirror (M3), which has an estimated completion date in 2027. This mirror system will allow for better quality of observations over a larger field of view. The dome and
telescope structure are on track to be completed by
2026.
NASA JPL discovers two types of comets that move like asteroids and discover dark comets.
These celestial objects look like asteroids but act like comets now come in two flavors.
www.jpl.nasa.gov
Dec. 9, 2024
These celestial objects look like asteroids but act like comets now come in two flavors.
The first dark comet — a celestial object that looks like an asteroid but moves through space like a comet — was reported less than two years ago. Soon after, another six were found. In a new paper, researchers announce the discovery of seven more, doubling the number of known dark comets, and find that they fall into two distinct populations: larger ones that reside in the outer solar system and smaller ones in the inner solar system, with various other traits that set them apart.
The findings were published on Monday, Dec. 9, in the Proceedings of the National Academy of Sciences.
Scientists got their first inkling that dark comets exist when they noted in a
March 2016 study that the trajectory of
“asteroid” 2003 RM had moved ever so slightly from its expected orbit. That deviation couldn’t be explained by the typical accelerations of asteroids, like the small acceleration known as the
Yarkovsky effect.
“When you see that kind of perturbation on a celestial object, it usually means it’s a comet, with volatile material outgassing from its surface giving it a little thrust,” said study coauthor Davide Farnocchia of NASA’s Jet Propulsion Laboratory in Southern California. “But try as we might, we couldn’t find any signs of a comet’s tail. It looked like any other asteroid — just a pinpoint of light. So, for a short while, we had this one weird celestial object that we couldn’t fully figure out.”
Weird Celestial Objects
Farnocchia and the astronomical community didn’t have to wait long for another piece of the puzzle. The next year, in 2017, a NASA-sponsored telescope discovered history’s first documented celestial object that originated outside our solar system. Not only did
1I/2017 U1 (‘Oumuamua) appear as a single point of light, like an asteroid, its trajectory changed as if it were outgassing volatile material from its surface, like a comet.
“‘Oumuamua was surprising in several ways,” said Farnocchia. “The fact that the first object we discovered from interstellar space exhibited similar behaviors to 2003 RM made 2003 RM even more intriguing.”
By 2023, researchers had identified seven solar system objects that looked like asteroids but acted like comets. That was enough for the astronomical community to bestow upon them their own celestial object category: “
dark comets.” Now, with the finding of seven more of these objects, researchers could start on a new set of questions.
“We had a big enough number of dark comets that we could begin asking if there was anything that would differentiate them,” said Darryl Seligman, a postdoctoral fellow in the department of Physics at Michigan State University, East Lansing, and lead author of the new paper. “By analyzing the reflectivity,” or albedo, “and the orbits, we found that our solar system contains two different types of dark comets.”
Two Kinds of Dark Comets
The study’s authors found that one kind, which they call outer dark comets, have similar characteristics to
Jupiter-family comets: They have highly
eccentric (or elliptical) orbits and are on the larger side (hundreds of meters or more across).
The second group, inner dark comets, reside in the inner solar system (which includes Mercury, Venus, Earth, and Mars), travel in nearly circular orbits, and are on the smaller side (tens of meters or less).
Like so many astronomical discoveries, Seligman and Farnocchia’s research not only expands on our knowledge of dark comets, but it also raises several additional questions: Where did dark comets originate? What causes their anomalous acceleration? Could they contain ice?
“Dark comets are a new potential source for having delivered the materials to Earth that were necessary for the development of life,” said Seligman. “The more we can learn about them, the better we can understand their role in our planet’s origin.”
For more information about asteroids and comets, visit:
https://www.jpl.nasa.gov/topics/asteroids/
There was another lunar impact flash tonight. I filmed it at 360fps from my home at 22:34:35 on December 8, 2024 (slow playback) and was able to confirm it with multiple telescopes. Bright meteors and fireballs have been appearing every day, but lunar impact flashes have also been captured one after another.
Related:
Session Date: December 1st 2018
Laura, Andromeda, and Artemis at the board
Pierre, Joe, Chu, Ark, Possibility of Being, Alana, Gaby, Scottie, Niall, Princess Leia, Pikabu
Q: (L) So today is... What is today?
(Artemis) December 1st!
(L) Oh, that's right! How could I forget? It's Chu's birthday. We were just having a birthday party, and here I'm asking what day it is. Well, that just tells you that I'm getting decrepit.
(Artemis) You have an excuse! When young people do it, it's like, "Oh, you're retarded!"
(L) We have only 30 days left in 2018. I can't believe the whole year is gone...
July 4, 1998
Frank, Ark, Laura.
Q: Hello.
A: Hello.
Q: And who do we have with us this evening?
A: Higurrah.
Q: And where do you transmit through?
A: Cassiopaea.
Q: (A) I am trying to write down some things about a cosmology, and I have some questions mainly about the coming events. First there was the story of the sun's companion brown star which is apparently approaching the solar system, and I would like to know, if possible, details of its orbit; that is, how far it is, what is its speed, and when it will be first seen. Can we know it? Orbit: how close will it come...
www.sott.net
