Space, in brief

Europe's Vega-C rocket lifted off from French Guiana at 01:21 GMT on 15 September, on a flight called VV30. [3][4]

It carried two satellites that watch Earth: ESA's FLEX and Sentinel-3C, part of the European Union's Copernicus programme. [1]

It was Vega-C's first launch of two satellites at once. They were stacked inside the nose cone with an adapter called Vespa. [4]

Sentinel-3C was released first and FLEX about an hour later. ESA's control centre in Germany then received a first signal from each. [1]

FLEX is ESA's first satellite built to measure photosynthesis from space. Photosynthesis is how plants turn sunlight and carbon dioxide into the energy they live on. [1]

Plants send back a tiny part of the sunlight they absorb as a faint red glow, far too weak for human eyes. [5]

That glow can change when a plant is short of water or attacked by pests, before its leaves visibly wilt. [5]

ESA's Simonetta Cheli said FLEX and Sentinel-3C will fly about 1 km and a few seconds apart. [2] The Sentinel-3 satellite beside FLEX measures clouds, haze, water vapour and ground temperature. [6]

Sentinel-3C is the third satellite of its kind. The first two, launched in 2016 and 2018, are still working. [3]

It measures oceans, land, ice and air, and its data feeds ocean and weather forecasts. [8] Eumetsat, Europe's weather-satellite agency, will run it with ESA. [1]

The Italian company Avio builds Vega-C and ran this launch itself. [9] It was only the second Vega-C flight Avio has managed without Arianespace, Europe's main launch company. [2][3]

Before this flight, Vega-C had flown seven times since July 2022, and six of those flights worked. [3] Its top stage uses an engine made in Ukraine. [2]

Why it matters. Watch whether ESA's checks over the coming days find both satellites healthy and working as expected. [1]

NASA says its new Nancy Grace Roman Space Telescope has fuel for at least 22 years of science, more than double its 10-year plan. [10] Its first course-correction burn on 31 August used about 18 kg of fuel, against 200 kg set aside. [10] The telescope also launched lighter than budgeted, 8,056 kg instead of 9,800 kg, so the team filled its tanks. [10] A second, smaller burn is due later this month, and Roman should reach its working orbit around early December. [10]

Why it matters. Fuel is the main thing Roman uses up as it works. So the saved fuel could mean extra years of pictures after its 10-year design life. [10]

A team including Ryan Camilleri of the University of Queensland built a catalogue of almost 3,000 type Ia supernovas, which are exploding dead stars called white dwarfs. [11] These blasts all shine with nearly the same brightness, so their light shows how far away they are. [11] The team combined 30 years of observations from different telescopes, correcting for dust and for light bent on the way. [11] It found more evidence that dark energy, the unknown push speeding up the universe's growth, may change over time. [11]

Why it matters. The standard picture of the universe assumes dark energy never changes. [11] A separate survey called DESI found a similar hint in 2024, so two independent methods have now found hints that it changes. [11]

In November 2023 the LIGO detectors, which sense ripples in space called gravitational waves, caught two black holes merging. [12] The signal, GW231123, seemed to come from black holes of 140 and 100 times the Sun's mass, which most models struggle to explain. [12] A study published on 25 August says a heavy object in between may have bent and magnified the ripples. [12] Allowing for that, the whole system comes out at about 140 Suns, not 240. [12]

Why it matters. If it holds, the black holes need no unusual explanation. [12] But the team cannot say what did the bending, and single objects that heavy should be very rare. [12]

Fast radio bursts are flashes of radio waves that last from a few thousandths of a second to a few seconds and come from billions of light-years away. [13] On the way to Earth they pass through gas, and denser gas spreads each signal out more. [13] A Caltech team led by Kritti Sharma used 114 bursts to measure how gas pushed out of galaxies smooths out the matter between them. [13] The paper appeared in the journal Nature Astronomy. [13]

Why it matters. That smoothing looks very like the effect of dark energy or of neutrinos, so it has to be measured before those can be. [13] A Caltech radio array due in 2029 is expected to find tens of thousands more bursts. [13]

In October 2022 the brightest gamma-ray burst ever seen, called GRB 221009A, reached Earth from more than two billion light-years away. [14] A detector called Carpet, in Russia's Caucasus mountains, caught the highest-energy particle of light ever recorded from such a burst. [14] Known physics says faint leftover light from the Big Bang should have destroyed it on the way. [14] An Italian team says it may have survived by briefly turning into a very light, undetected particle, if one of Einstein's rules breaks at huge energies. [14]

Why it matters. The team notes the particle arrived about an hour after lower-energy light from the burst, as its idea predicts. [14] The paper has been accepted by the journal Physical Review Letters, but the particles it needs have never been detected. [14]

Venus and Mercury are the only planets in the solar system with no moon. [15] Stephen Kane of the University of California, Riverside simulated what would happen to a moon of Venus over billions of years. [15] In most runs the moon spiralled inward and was torn apart by the planet's gravity. [15] It survived only if early Venus spun fast, with a day shorter than about 12 hours, and the moon was no heavier than Earth's. [15]

Why it matters. Those conditions do not match what scientists think early Venus was like. [15] NASA's planned DAVINCI probe will measure the gases in Venus's air, where a lost moon might have left a chemical trace. [15]

NASA's Office of Inspector General, the agency's internal auditor, published an overview of its reports on 10 September. [16] It says both US cargo ships that supply the International Space Station, SpaceX's Cargo Dragon and Northrop Grumman's Cygnus, now launch on SpaceX's Falcon 9 rocket. [16] Boeing's Starliner capsule still has no certificate to carry astronauts, and its next flights are uncertain. [16] The office says it is now examining how NASA manages its cargo contracts. [16]

Why it matters. A June 2026 audit questioned $128 million in early payments to Boeing. [16] The station is due to be retired in 2031, so NASA has only a few years to get use out of Starliner. [16]

In June the US government set up a science advisory council on UAP, the official name for UFOs. [17] Its chair, the Harvard astrophysicist Avi Loeb, told Space.com the council met privately on 31 August at the Office of the Director of National Intelligence. [17] He said he cannot disclose what was discussed. [17] A Gallup poll in July found that 49% of Americans think every UFO sighting has an ordinary, earthly explanation. [17]

Why it matters. Loeb said the US government is sincere about studying UAP by collecting scientific data. [17] Council member Ben Lamm, who runs the gene-editing company Colossal Biosciences, said findings would be shared openly. [17]

In May 2024 a fishing boat sank about 40 miles off the coast of Mississippi, and one of its crew switched on a personal locator beacon. [18] Its distress call went to SARSAT, a search-and-rescue system carried on satellites, which passes the location to the nearest ground station. [18] The crew was saved. [18] NASA's Goddard centre first developed the system's technology, and it began working in 1982. [18]

Why it matters. Today 62 satellites and 45 nations take part, and more than 63,000 lives have been saved. [18] It works far out at sea, where a phone has no signal. [18]

On Monday NASA astronaut Anil Menon soldered parts onto a circuit board aboard the International Space Station, using a lead-free experiment called MIYOKA. [19] The samples will come back to Earth and be compared with identical ones soldered on the ground. [19] ESA astronaut Sophie Adenot tested a new European exercise machine, and two Russian crew members ran hearing and balance tests. [19] Commander Jessica Meir cleared storage space for the coming arrival of SpaceX's Crew-13. [19]

Why it matters. If electronics can be repaired in orbit, the station would rely less on costly supply flights. [19]

NASA's 10 astronaut candidates, introduced in September 2025, are about halfway through nearly two years of training. [20] This summer they studied rocks in New Mexico and Iceland, because future Moon crews will collect samples. [20] They also flew NASA's WB-57 high-altitude planes and T-38 jets, practised water survival and took Russian classes. [20] The class is due to graduate in 2027 and then wait for flight assignments. [20]

Why it matters. Its members could later work on the space station or fly on Artemis missions to the Moon. [20]