posted 08-12-2025 06:55 AM               

quote:

---

Originally posted by SpaceAholic:
...the newly discovered interstellar object 3I/ATLAS, which will pass on March 16, 2026 within a distance of 53.6 million kilometers from Jupiter.

---

posted 10-24-2025 01:10 PM               

Some are hinting at a worldwide blockade of scientific information and images concerning 3I Atlas as this object passed fairly close to Mars with opportunities for imaging as it was passing the red planet.

posted 10-24-2025 02:48 PM               

No comets have jets or tails pointing towards the Sun; all comet tails and jets point away from the Sun. This is because the solar wind and solar radiation pressure push the gas and dust particles released from the comet away from the Sun, regardless of the comet's direction of travel.

Comet tails always point away from the Sun. This is a fundamental characteristic of comets, driven by solar forces.

Solar wind pushes the material. The solar wind, a stream of charged particles from the Sun, pushes the gas and dust particles away from the Sun.

posted 10-24-2025 06:11 PM               

While comets do warm up when they get close to the sun, they don't warm up in all spots in the same fashion. The areas facing the sun heat up fastest, and if there is a weaker area on the surface of the comet, sublimated gases under the surface can burst through — causing these sun-facing jets.

posted 10-28-2025 08:54 AM               

As for comet's tails, most have two distinct tails - the ion tail which points away from the sun, and a dust tail that may curve at a different angle.

Depending on the path of the comet relative to the Earth and the sun there will sometimes also be an "anti-tail" visible. In reality this is us seeing one part of a disc of particles around the comet in its orbital plane side-on, lit up by the sun. This apparent spike may point towards the sun, with the other side of it more-or-less hidden by the main tail.

posted 11-20-2025 08:40 AM               

View Interstellar Comet 3I/ATLAS Through NASA's Multiple Lenses

NASA is in the midst of an unprecedented solar system-wide observation campaign, turning its spacecraft and space telescopes to follow comet 3I/ATLAS, the third known interstellar object to pass through our solar system. Twelve NASA assets have captured and processed imagery of the comet since it was first discovered on July 1, and several others will have opportunities to capture more images as the comet continues to pass through our solar system.

By observing the comet from so many locations, NASA has an opportunity to learn about the ways that 3I/ATLAS differs from our solar system's home-grown comets and give scientists a new window into how the compositions of other systems may differ from our own.

Observations from Mars

The closest imagery of the comet was taken by NASA's spacecraft at Mars. Earlier this fall, 3I/ATLAS passed by Mars from a distance of 19 million miles, where it was observed by three NASA spacecraft. The Mars Reconnaissance Orbiter (MRO) captured one of the closest images of the comet, while the MAVEN (Mars Atmosphere and Volatile EvolutioN) orbiter obtained ultraviolet images that will help scientists understand the comet's make-up. Meanwhile, the Perseverance rover grabbed a faint glimpse from the surface of Mars.

Sun watchers' view

Some of NASA's heliophysics missions have the unique ability to observe areas of the sky near the Sun, which allowed them to track comet 3I/ATLAS as it passed behind our Sun as seen from Earth, making observations with ground-based telescopes impossible. NASA's STEREO (Solar Terrestrial Relations Observatory) captured images from Sept. 11 to Oct. 2, and the ESA (European Space Agency) and NASA mission SOHO (Solar and Heliospheric Observatory) observed the comet from Oct. 15 to 26. Images from NASA's PUNCH (Polarimeter to Unify the Corona and Heliosphere) mission, which launched earlier this year, reveal the comet's tail during observations from Sept. 20 to Oct. 3.

Despite previously observing and discovering thousands of comets, this is the first time NASA's heliophysics missions have purposefully observed an object originating in another solar system.

Asteroid explorers

NASA's Psyche and Lucy spacecraft, currently on their respective outbound journeys to study various asteroid targets throughout the solar system, were able to observe 3I/ATLAS en route. On Sept. 8 and 9, Psyche acquired four observations of the comet over eight hours from a distance of 33 million miles. These images will help scientists refine the comet's trajectory. On Sept. 16, Lucy took a series of images from 240 million miles away. Stacking these images together provides detail on the comet's coma and tail.

The NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope in Chile discovered 3I/ATLAS on July 1. Later that month it was viewed by NASA's Hubble Space Telescope. In August, both NASA's James Webb Telescope and SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) captured imagery.

Comet 3I/ATLAS will fly closest to Earth about Friday, Dec. 19, at 170 million miles, which is almost twice the distance between the Earth and Sun. NASA spacecraft will continue to observe the comet as it makes its journey through the solar system, passing the orbit of Jupiter in spring 2026.