Space, in brief

NASA will not launch the Artemis III crew until Blue Origin's Moon lander is in orbit. [1]

Jared Isaacman, head of NASA, the US space agency, said this to NASASpaceflight, a news site. [1]

Blue Origin, a rocket company, will launch its Blue Moon lander first. [1]

Blue Moon can wait in orbit for about 30 days while engineers check it. [1]

Blue Origin has only carried people on New Shepard, which hops up and back down. [1]

So Artemis III is Blue Origin's first test of keeping people alive for long. [1]

NASA hopes Artemis IV, in 2028, will land the first astronauts on the Moon since 1972. [2]

Systems engineers call this retiring risk: checking the least-proven part before any step that is final. [1]

Here the least-proven part is Blue Moon, so it flies first and SLS waits. [1]

Blue Origin gains NASA staff, cargo planes and patience to finish its lander. [1]

NASA pays in time: its crew flight waits on a lander not yet fully assembled. [1]

Next, Blue Origin must finish building its test lander, then launch it on New Glenn. [1]

A firm order of launches sounds like a schedule that is on track, even though the first piece in it has not been fully built. [1]

The crew flight cannot start until Blue Moon is in orbit and checked, and Isaacman would accept a month's delay to learn more. [1]

Its Starship flies last on Artemis III and adds practice, while Blue Origin's lander is the test the crew launch waits on. [1]

When Blue Origin's test Blue Moon lander will be fully built.

Isaacman said there is no fully assembled test lander yet, and he gave no date for one. [1]

When New Glenn can fly again from Blue Origin's damaged Florida pad.

The BBC reported in June that rebuilding the pad would take many months, and the interview gave no new date. [1][2]

Whether NASA's 2028 Moon landing date holds.

Artemis IV's landing depends on Artemis III flying first, and Artemis III now waits on Blue Moon. [1][2]

NASA sent hundreds of its own staff, welders among them, to help Blue Origin repair its damaged Florida launch pad.

Astronomers led from Queen's University Belfast found new Trojan asteroids that trail behind Neptune. [3]

Trojans are rocks that share a planet's path round the Sun, ahead of or behind it. [3]

Jupiter's Trojans were first seen in 1906. [3]

The team used early test images from the Rubin Observatory, a new telescope in Chile. [3]

It identified 2 of these asteroids and 1 more possible one. [3]

That doubled the known trailing Trojans on orbits that last a very long time. [3]

Their colours showed the leading and trailing groups have similar surfaces. [3]

For ten years this group sat in front of the bright centre of our galaxy. [3]

These rocks are thought to be leftovers from when the planets formed. [3]

The third object stays only a possible Trojan until more sightings confirm it. [3]

Rubin's survey runs 9 more years and should find tens to hundreds more. [3]

Its early test images doubled the known trailing Neptune Trojans, a first sign of what its nine-year survey can find. [3]

Whether Rubin's third object near Neptune is a real Trojan.

It is listed only as a possible member so far. [3]

Early images from the new Rubin Observatory in Chile doubled the number of known Trojan asteroids trailing Neptune on long-lived orbits.

Ceres may hold 30 to 50 percent more salt than earlier readings showed, a study says. [4]

Ceres is a dwarf planet and the largest object in the main asteroid belt. [4]

NASA's Dawn spacecraft studied it from 2015 to 2018 and saw bright salty spots. [4]

Two Caltech researchers combined Dawn's data with computer models of how the surface changes. [4]

They found water ice mixed in with the salt can hide it from view. [4]

Salty ice turns straight to gas faster, and the gas drifts to colder ground. [4]

The salt stays behind, so bright spots grow saltier over time. [4]

Landslides keep uncovering fresh ice, which keeps this going. [4]

Ceres' bright salt marks past water activity at its surface, so the amount matters. [4]

Planetary scientists call ice turning straight to gas sublimation. [4]

The result rests on models and Dawn's old data, since Dawn's work ended in 2018. [4]

Why ice on a cold world gathers in the coldest spots and leaves its salt behind

With little or no air pressing on it, ice skips melting and turns straight into gas. Scientists call this sublimation.

Warmer ice turns to gas much faster than colder ice.

The gas drifts and freezes again on the coldest ground nearby, which is called a cold trap.

Anything that cannot turn to gas, like salt or dust, stays behind as a crust, which geologists call a lag.

So over many seasons, ice gathers in the coldest, shadiest spots and salt builds up in the warmer ones.

Ice on a cold world keeps leaving warm ground and settling on cold ground.

Each dot is one crater near Mars's north pole, pictured from 2006 to 2025. The filled ones showed their ice changing.

Salty ice on Ceres turns to gas faster, the gas moves to colder ground, and the salt left behind makes the bright spots saltier.

Ice on the crater floors grows in the cold months and shrinks in the warm ones, and each crater's own shape and shade decide how much.

The water ice LUMINA looks for sits in Moon craters that never see sunlight, the coldest ground there, which is where a cold trap collects it.

On Earth, thick air and warmth usually melt ice into water first, so this sorting is clearest on cold worlds with little or no air.

Planners choosing Moon landing sites are looking for ice that drifted into the darkest craters over millions of years.

The rest of the day is science, where new looks at old spacecraft data and early telescope images changed what scientists think about Ceres's salt, Mars's crater ice and Neptune's Trojan asteroids. [3][4][5]

Dawn's data from 2015 to 2018 and HiRISE pictures from 2006 to 2025 gave new results without a new launch. [4][5]

How much salt Ceres really holds.

The 30 to 50 percent figure comes from models run on Dawn's data, and Dawn's work there ended in 2018. [4]

Ice on the floors of craters near Mars's north pole grows and shrinks with the seasons. [5]

Researchers studied pictures of 36 craters taken by NASA's Mars Reconnaissance Orbiter. [5]

The pictures came from its HiRISE camera, between 2006 and 2025. [5]

Bright ice deposits changed in 32 of the 36 craters. [5]

In the other 4, the brightness did not change. [5]

Mars's northern cap is water ice; its southern cap is frozen carbon dioxide. [5]

A year on Mars lasts 668 Earth days. [5]

The changes differed from crater to crater, the team found. [5]

So each crater's own shape and weather likely matter more than Mars's overall climate. [5]

Planetary scientists call a small area's own weather a microclimate. [5]

Frost on the ground outside a crater may also change how bright it looks. [5]

Ice on the crater floors grows in the cold months and shrinks in the warm ones, and each crater's own shape and shade decide how much.

Why 4 of the 36 Mars craters showed no change.

The study saw no change in their brightness, and frost on the ground outside a crater can also change how bright it looks. [5]

Exploding stars may have slowed the clearing of the early universe's fog, not caused it. [6]

About 400,000 years after the Big Bang, the first atoms formed and filled space like fog. [6]

Ultraviolet light from the first stars later broke those atoms apart and cleared it. [6]

Many thought winds from exploding stars, called supernovas, blew holes that let this light escape. [6]

Cody Carr of the University of Michigan led a team using the Hubble Space Telescope. [6]

They studied six galaxies 3.5 billion light-years away, stand-ins for early ones. [6]

In their first 3 million years, winds from young stars let the light out. [6]

Later, supernova winds stirred up gas that trapped the light instead. [6]

The study was published on 15 October in Nature Astronomy. [6]

It disagrees with most computer models, where the light escapes most after supernova winds start. [6]

Cosmologists call the clearing reionization: light strips electrons off hydrogen atoms. [6]

Six galaxies are a small sample, and the team wants more to check it. [6]

The Hubble study disagrees with models in which light escapes most after supernova winds start. [6]

Whether the universe's first galaxies behaved like the six that were studied.

The team used six galaxies 3.5 billion light-years away as stand-ins and says more are needed. [6]

On the night of 1 to 2 November, the Moon passes close to Mars and Jupiter. [7]

They sit in Leo, a group of stars also called the Lion. [7]

About an hour after midnight, the Moon is less than 5 degrees from Mars. [7]

That gap is about the width of three fingers held at arm's length. [7]

From Australia and Indonesia, the Moon will pass in front of Jupiter and hide it. [7]

Astronomers call this an occultation; it starts at 20:45 GMT on 2 November. [7]

On 3 November, parts of South America see the Moon cover Regulus, a bright star. [7]

Which part people see depends on where on Earth they stand. [7]

The Moon looks biggest, yet it is less than half as wide as Mars. [7]

Jupiter is more than 20 times wider than Mars. [7]

Researchers at Ohio State University built an AI tool to choose safe Moon landing sites. [8]

It is called LUMINA, and it was presented at a meeting of planetary scientists. [8]

Gokce Inal, a PhD student at Ohio State, led the study. [8]

LUMINA weighs slopes, hazards, rock types and science value. [8]

It also looks for water ice, which astronauts could use for drinking, oxygen and fuel. [8]

Water ice on the Moon sits in craters that never see sunlight. [2]

LUMINA then compares the possible sites with each other to rank them. [8]

It builds on an earlier tool by the same group that describes Moon photos. [8]

NASA plans to land astronauts on the Moon in 2028, for the first time since 1972. [8]

Inal says AI will help people sort the millions of images future missions will bring. [8]

It is still a research tool, and the team hopes to use it for Mars too. [8]

The water ice LUMINA looks for sits in Moon craters that never see sunlight, the coldest ground there, which is where a cold trap collects it.

LUMINA ranks landing sites by hazards, science value and water ice in one tool. [8]

Two staff at Armagh Observatory and Planetarium, in Northern Ireland, now have asteroids named after them. [9]

Rok Nezic, who grew up in Slovenia, works there as a tours and outreach officer. [9]

His asteroid, (20560) Nezic, is 10.9 km across and was found in New Mexico in 1999. [9]

Shane Kelly has written down the observatory's weather readings by hand since 1999. [9]

His asteroid, (7050) Shanekelly, is 15.6 km across and was found in Chile in 1982. [9]

The number in an asteroid's name shows the order in which it was found. [9]

Two people nominated Nezic for the honour. [9]

Armagh now counts 29 asteroids with some link to the observatory. [9]

The International Astronomical Union decides names; discoverers can propose one once an orbit is known well. [9]

The biggest asteroids were found first, so the ones found now keep getting smaller, Nezic says. [9]

Surveys that find asteroids also show which ones will not hit Earth, he says. [9]

Kelly has entered more lines of weather data by hand than any of his 17 predecessors. [9]

Armagh plans a new dome that will show the two asteroids and their orbits. [9]