Space, in brief

Old spacecraft reaching the end

NASA shut down Swift after 22 years, once a rescue craft failed to lift it. [1] NASA formally ended its OSIRIS-REx asteroid mission on 30 September, though the craft flies on to the asteroid Apophis. [9]

Military satellites needing rides

The US Space Force moved six launches from Vulcan, a delayed US rocket, to SpaceX. [3] China put seven Yaogan satellites into orbit on one day, 23 October. [4]

Telescopes watching things change

The Webb telescope caught a far supernova four to ten days after it blew up, by looking at one patch of sky again and again. [7] Over 11 hours Webb also watched water clouds shift on WISE 0855, a failed star. [5] A 2016 burst in Swift's records came in two parts that look like two different kinds. [2]

1. 1NASA shuts down its Swift telescope after a failed rescue; it falls back to Earth in November, 22 years after launch
2. 2Six military launches move to SpaceX
3. 3China sends up seven spy satellites in a day
4. 4NASA changes how it picks science missions
5. 5NASA closes the OSIRIS-REx asteroid mission

NASA has shut down Swift, a space telescope whose orbit was decaying, which means it was slowly sinking towards Earth, SpaceNews reported on 24 October. [1]

The next marker is Swift's fall into the atmosphere, which SpaceNews says is expected in November. [1]

The US Space Force has moved six military launches from Vulcan, the rocket of United Launch Alliance (ULA), to SpaceX rockets, SpaceNews reported on 24 October. [3]

Among them, a new missile-warning satellite and the payloads for an experimental mission to watch the space between Earth and the Moon now fly on SpaceX's Falcon Heavy. [3]

SpaceNews says the reshuffle was prompted by Vulcan's delays. [3]

In return, ULA will get later missions that had been booked on SpaceX rockets. [3]

So SpaceX flies more US military satellites now, and ULA keeps work for when Vulcan is flying again.

China made two launches on Friday 23 October, SpaceNews reports. [4]

The first carried Yaogan-50, which SpaceNews calls a spy satellite, into a strongly retrograde orbit, one that runs against the direction Earth spins. [4]

A Long March 4B rocket then lifted off from Jiuquan, a launch site in northwest China, with six more Yaogan satellites in two groups of three. [4]

A retrograde orbit costs a rocket extra fuel, because it cannot borrow the speed of Earth's spin.

That is seven Yaogan satellites in orbit in one day. [4]

Rockets rarely fly this way because of the fuel cost, and the readable part of the SpaceNews report does not say what Yaogan-50's path is for. [4]

NASA has announced an overhaul of how it asks for and chooses ideas for science missions, The Planetary Society reported on 23 October. [8]

NASA says the aim is to choose missions and start building them faster. [8]

Its leaders will explain the changes and take questions at an online NASA Science Town Hall on Monday 26 October, the first in two years. [8]

It comes as NASA skips its 2026 round of ROSES, a programme that usually pays for hundreds of millions of dollars of research. [8]

Scientists at US universities and research institutes compete for these missions and grants. [8]

The town hall on 26 October is the first chance for them to hear how the new rules work.

NASA formally ended OSIRIS-REx on 30 September, Space.com reported on 20 October. [9] It was the first US mission to collect a piece of an asteroid and bring it to Earth. [9]

It scooped rock from Bennu, an asteroid about 490 metres wide, and its capsule landed in the Utah desert on 24 September 2023 with 121.6 grams, more than twice its target. [9]

More than 200 research papers have come from the sample, which holds amino acids and sugars. [9]

The spacecraft still has fuel, so it has been renamed OSIRIS-APEX and is flying to Apophis, another asteroid, due in 2029. [9]

Most of the Bennu sample is being kept for future scientists, and lead scientist Dante Lauretta says it will be studied with instruments not yet built. [9]

Gamma-ray bursts are among the most powerful flashes in the universe, and astronomers sort them into two kinds. [2] Long ones, over two seconds, usually come from a giant star collapsing. [2]

Short ones, under two seconds, come from two small, dense stars merging. [2]

A study in Nature Astronomy on 23 October describes GRB 160425A, a burst that came in two parts four minutes apart. [2]

Nearly every standard test puts the short first part with mergers and the long second part with collapses. [2]

One event carrying signs of both causes does not fit the way bursts are sorted now. [2]

The authors, working from Swift's readings and those of NASA's Fermi telescope, say the sorting may need rethinking. [2]

A far object is one dot, but its parts brighten, dim and change colour at different times, so watching the dot change pulls the parts apart.

Watching when and how its light changes can split it into its parts, even when the object stays a single dot.

Most of what any of us knows about far-off things, from a storm out at sea to a relative's heart, comes from changes that someone kept watching for.

The James Webb Space Telescope has spotted AT 2026abck, an exploding star whose light left it about 1.15 billion years after the Big Bang, Live Science reported on 20 October. [7]

It was not there when Webb looked on 28 May, and it was there on 7 August. [7]

The team thinks it saw the blast four to ten days after it began. [7]

At its peak it shone about 8 billion times brighter than the Sun, says co-author Xiaohui Fan. [7]

The paper was posted online on 29 September and has not yet been checked by other scientists. [7]

The universe has stretched since that light set out, so the blast plays out about six times slower for us: 71 days on Earth were about 12 at the star. [7]

Most supernovas this far away are found with a galaxy cluster magnifying them, and this one was not. [7]

A team led by Brittany Miles of the University of Arizona watched WISE 0855, the coldest known brown dwarf, for 11 hours with the Webb telescope. [5]

A brown dwarf is a failed star: too heavy to be a planet, too light to burn like the Sun. [5]

WISE 0855 is 7.2 light years away and about -8C at the top of its air. [5]

In 44 snapshots, light from carbon monoxide swung by 10% while light from water barely changed. [5] One pattern explains 60.5% of the change, and a second, from deeper down, 4.7%. [5]

Computer models fit the readings far better with patchy water-ice clouds near the top of its air. [5]

The University of Arizona calls it the first sighting of changing water clouds outside our solar system, and the team wants about 20 more hours to learn how fast it spins. [5]

Astronomers followed a black hole pulling gas off a nearby star as an outburst from it faded, in a study in Nature Astronomy on 22 October. [6]

At the peak the system shone at about a fifth of the brightest a black hole can glow before its own light starts pushing gas away. [6]

Then its light looked cool, with strong signs of hydrogen and helium. [6] As it dimmed, the light switched to hot and almost featureless. [6]

The team says a puffed-up inner disk of gas had been shading the outer disk from the black hole's strongest light, and similar systems suggest it may be common. [6]

If so, it changes how astronomers work out how fast black holes spin. [6]

Algol, a star in the constellation Perseus nicknamed the Demon Star, dims every 2.867 days, Space.com notes in a Halloween sky guide. [10]

It is really two stars, and the dimming comes when one passes in front of the other. [10]

At its faintest Algol is 3.3 times dimmer than usual, and each dip lasts about 10 hours. [10] Around Halloween it dims on 29 October and on 1 November. [10]

Around the full Moon on 26 October, bright streaks also show around the craters Tycho, Copernicus and Kepler. [10]

They are rock flung out by the impacts that made those young craters, and both sights need no telescope. [10]

A fuelling test for the rocket that will carry Artemis III, NASA's next crewed flight, is now planned several months from now, NASASpaceflight reported on 24 October. [11]

It had once been expected around this time. [11]

The test checks redesigned fuel connections at the base of the Space Launch System (SLS), NASA's Moon rocket, where hydrogen leaked before both earlier Artemis flights. [11]

Its orange core stage is due to go between the two side boosters next week. [11]

For the test, a short stack with no upper stage and no Orion capsule will roll to the launch pad and be filled with fuel. [11]

NASA still aims to fly Artemis III no earlier than summer 2027. [11]