An image of the surface of Europa. The top half of the sphere is illuminated with the bottom half dark. The surface is traced with lineae, long lines across its surface of various hues of grey, white, and brown. The surface is a brown-grey, somewhat like Earth's Moon with the highest brightness areas appearing white.

Evidence For Water Vapor Plumes On Europa Vanishes In Re-Analysis

June 11, 2026 by Maya Posch 18 Comments

Unlike on Mars where for decades we have had dozens of orbital and ground-based platforms zipping and scurrying about to prod at every bit of emitted radiation, rock type and twitch of dust devils in its thin atmosphere, for other planets and their moons we have to do a lot more speculative interpretation of data. Such was the case with the presumed existence of water plumes on Jupiter’s moon Europa. These now appear to have been a statistical fluke, per research by [L. Roth] et al. in Astronomy & Astrophysics.

As succinctly summarized in the article on this by [Javier Barbuzano] of Sky and Telescope, the original 2013 finding of said water plumes by the same team was based on faint UV emissions from Europa’s southern hemisphere as captured by the Hubble Space Telescope. However, in more recent captures these emissions were not detected again, leading them to reexamine their original analysis of the 2013 data.

One of the main flaws was in the assumption of where Europe was located on Hubble’s 1,000 x 1,000 resolution detector, with the re-analysis showing that they were off by a couple of pixels. A second flaw was quite understandable as since 2013 we have learned that Europa has a thin hydrogen exosphere which interacts with the Sun’s UV radiation. The resulting scattering induces a UV glow which could be mistaken for UV radiation emanating from the moon’s surface.

Even with this one intriguing feature turning out to be a mirage, it doesn’t make Europa any less interesting as it’s still assumed to have vast liquid water oceans. Along with Uranus’ moon Miranda this makes it very worth it to experience more of the sights and sounds of these alien worlds, whether in person or via our robotic friends.

NASA Announces Artemis III Crew And Ambitious Goals

June 10, 2026 by Tom Nardi 28 Comments

When the Artemis lunar program was first conceived, the third mission would have seen astronauts step foot on the Moon for the first time since Apollo 17 in 1972. But as hard as getting into space is, a sojourn to our nearest celestial neighbor is even more mindbogglingly complex, and so earlier this year it was announced that actually landing on the Moon would be pushed out to the fourth mission.

In turn Artemis III would take a page out of the Apollo 9 playbook and test out rendezvous and docking procedures with commercial landers while operating in the relative safety of low Earth orbit. Moving the target date for the landing a few years down the road gave all involved parties a little more breathing room, but it also provided a valuable opportunity to gain insight into the performance of the vehicles and systems ahead of the critical moment. In the original timeline, the first time Orion would attempt to dock with the lander would have been just before descending to the lunar surface — leaving precious little time to troubleshoot should anything go wrong.

Yesterday NASA held a press conference to update the public on their progress towards the planned 2027 launch of Artemis III, which included the long-awaited announcement of the crew that will kick the tires on the next-generation lunar landers being developed by SpaceX and Blue Origin

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Deep Dive Into Sputnik

June 9, 2026 by Al Williams 9 Comments

If you are an American of a certain age, you know the Soviet Union launched the first satellite, Sputnik, beating the United States to orbit. You might even remember ham radio operators tuning into the satellites beeping. But you probably haven’t heard much about the team that built the vehicle, the problems they had, or the clever design choices they made. [Hoog] has a video that details the birth of Sputnik. You can see the video below.

The original plan was to launch a massive space lab, but it proved too ambitious. Keep in mind that in the late 1950s, you didn’t have tiny computers, high-density power sources, or advanced materials, and no one really knew what to expect in the Earth orbit environment. Even the viability of radio from the ground to orbit wasn’t a given. But Sputnik’s 1-watt transmitter did the job.

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Questions Remain About Tense Moment Aboard ISS

June 9, 2026 by Tom Nardi 22 Comments

Even if you’re not normally interested in what’s happening in low Earth orbit, you probably heard that last week NASA ordered its personnel aboard the International Space Station to button themselves up in the docked Dragon spacecraft and await further instructions should they need to make a hasty departure. Known as Safe Haven, this emergency procedure is performed whenever there’s an elevated risk of damage to the Station.

NASA has provided an update on what happened, but it arguably leaves more questions than answers. Usually, crews go to their Safe Haven because some bit of space junk has wandered to close to the orbiting complex, but this time it was because Russian cosmonauts Sergey Kud-Sverchkov and Sergei Mikayev were getting ready to start cutting into the walls of the PrK transfer tunnel in an effort to address its persistent air leak.

After about an hour and a half, the Russians called off the effort and NASA gave their people the OK to leave the Dragon and return to their normal duties. NASA Press Secretary Bethany Stevens later posted on social media that the space agency would “look forward to working with Roscosmos on a collaborative approach to address the leaks” in the future. There’s currently no word on what a future repair attempt may entail, or when it would be attempted.

This is one of those things were we might not hear the full story for some time, but it sure does sound like not only did the Russians want to do something that NASA didn’t think was safe, but that the whole thing was sprung on them at the last moment. To give you an idea of how serious Mission Control was taking the situation, they decided to cram five people into a Dragon capsule that only has four seats — it certainly would have made for one wild ride down to Earth if they were given the order to evacuate.

What do you want to bet there were some frantic international calls taking place while the astronauts were hiding out in their designated lifeboat?

Discovery Of An Active Wind From The Milky Way’s Central Black Hole

June 8, 2026 by Maya Posch 12 Comments

One of the fun aspects of astrophysics is that much of it involves phenomena which you cannot exactly study from up close, with the supermassive black hole (SMBH) at the center of this galaxy – called Sagittarius A* (Sgr A) – being a great example. Although it’s been predicted since 1971 that black holes like Sgr A radiate energy which then pushes away nearby matter to create something akin to solar wind, this had so far not been proven. Now astronomers have discovered evidence for this emanating from Sgr A*.

Using five years worth of observations made with the Atacama Large Millimeter/Submillimeter Array (ALMA) and correlating it with other observations, a Southern Lobe of movement was identified, along with evidence for a Northern Lobe. Unlike a star where you are dealing with relatively massive quantities of matter being hurled into space, in the case of a very quiet SMBH like Sqr A* you are talking about occasional small wisps of gas of which a fraction gets turned into the radiation that then exerts pressure on the remaining gas.

It is speculated to be exactly this quiescent nature of Sgr A* that makes it so difficult to find evidence of SMBH wind, though one could also argue that having a well-fed SMBH whose event horizon rapidly expands would be fascinating from an astrophysics perspective, but less exciting for any nearby inhabited planets.

Attack Of The Atomic Oxygen

May 28, 2026 by Al Williams 20 Comments

While designing anything for operation in space has its challenges, there is at least one thing that is more of a problem for objects in Earth orbit than for deep-space probes: atomic oxygen. We like oxygen because we need it to live, but it is also highly reactive as a single atom. Luckily, on Earth, most of what we breathe is O₂. [Space Daily] talks about the challenges of the International Space Station dealing with the “space weather” of atomic oxygen in low Earth orbit.

Part of the problem is that even when we know better, we tend to think of the atmosphere coming to an abrupt end and space being a hard vacuum. But in reality, the atmosphere gradually dissipates, and at “only” 400 km above the Earth, the Space Station is really flying through a very thin atmosphere.

To compound the problem, this is above the ozone layer, so the Sun’s UV light rips O₂ into single oxygen atoms. Over time, these free oxygen atoms can affect many parts of a spacecraft exposed to them. Engineers first noticed that materials recovered from spacecraft had more damage and changes to material properties on the pieces facing the direction of travel. NASA has spent years testing different materials by mounting trays of different material samples outside the ISS.

Carbon-based polymers take a big hit from atomic oxygen exposure. Polymide film is frequently used, but it erodes with exposure. Carbon composites also lose mass. Other materials change in other ways. For example, an optical surface may roughen with exposure.

The usual answer is to over-design for mission objectives or to cover certain polymers with coatings like silicon dioxide or aluminum oxide, which are not as reactive to free oxygen. For a long-duration mission like the ISS, you may have to pay special attention to the materials in use. Very low satellites also need special care, as there is more oxygen in lower orbits.

There are other effects, too, such as extreme thermal cycles, debris strikes, and other indignities that space-traveling materials must withstand. But in deep space, atomic oxygen is a rare issue. Until, at least, we go somewhere else that has a lot of oxygen.

Decoding The Tianwen-2 Sample Return Mission’s Telemetry Signal

May 27, 2026 by Maya Posch No comments

China’s Tianwen-2 asteroid sample return mission launched on 28 May of 2025 and is scheduled to arrive at its target – near-Earth asteroid 469219 Kamo’oalewa – in June 2026. This gives folk back on Earth plenty of time to listen in on the probe’s communication with its home base, such as [Daniel Estévez] who recently had a poke at this telemetry as captured by the Dwingeloo radio telescope in the Netherlands.

With not a lot of public information on its trajectory it’s a hard probe to track, but now that it’s nearing its destination there’s an obvious part of the sky to aim for. This is X-band telemetry, broadcast at 8428.19 MHz, with the same basic modulation as its predecessor Tianwen-1.

Where it differs is in the coding, with Tianwen-2 also using concatenated coding, but having a frame length that’s better suited to submitting full Reed-Solomon codewords and does not require omitting bytes to make things awkwardly fit.

After analyzing the telemetry data itself, there doesn’t seem to be anything exciting contained within this capture. This does seem to be as expected considering that the probe is still in its coast phase where it doesn’t have to do much and likely is in a low-power state most of the time. Once its orbital insertion burn begins is when this knowledge can likely be used to track the mission in fine-grained detail, which is an event that we’re definitely looking forward to.