Blue Origin shows a 20-metre solar mast for a Moon base, and a Munich team designs a reactor for the two-week lunar night

The rest of the day

6 more stories on this beat.

Each with its own sources. None of these is a link to the story above.

1. 02

   Smile starts its science work

   Smile, a satellite run by the European Space Agency (ESA) and the Chinese Academy of Sciences, has been cleared to start its science work, ESA's science director Carole Mundell said. [4] It launched in May and flies a stretched orbit, from 5,027 km above Earth out to 120,920 km. [4] That keeps it far from Earth for about nine months of each year, with a steady view of the poles. [4] Its ultraviolet camera is the first since NASA's Polar spacecraft stopped in 2008 that can picture the whole ring of northern lights at once. [5]

   12

   0 km62,500 km125,000 km

   1. 1Closest point to Earth5,027 km
   2. 2Furthest point from Earth120,920 km

   Why it matters — Smile can now watch the northern lights for up to 45 hours at a time, the longest unbroken watch from space so far. [4] Its X-ray camera picks up stray light when it looks at Earth, so engineers are sending new software. [4] Its first good X-ray look at where the Sun's wind meets Earth's magnetic field is due in mid-October. [4]

2. 03

   Russia sets parachute tests for its new crew ship

   Russia says the crew ship meant to replace its Soyuz capsules will have its parachutes drop-tested in the country's Far East this autumn. [3] Dmitry Bakanov, head of Roscosmos, Russia's space agency, told the Russian news agency Interfax that tests of escaping an emergency on the launch pad follow later this year. [3] The ship has been worked on for nearly 20 years under several names, including Orel, Russian for eagle. The Interfax report calls it PTK NP. [3] They aim for a first crewed flight in 2028 or 2029, probably on an Angara A5M rocket. [3]

   Why it matters — Four years ago Russia's president, Vladimir Putin, spoke confidently about the ship and a return to the Moon, and neither has happened. [3] Russia also plans tests in 2027 at the point of launch where the air pushes hardest on a rocket, which Ars Technica reads as a sign of a test of escaping a rocket in flight. [3]

3. 04

   US military satellites due to launch

   SpaceX was scheduled to launch 21 satellites from California at 08:17 GMT on 5 October for the Space Development Agency, the US military office building a network of small satellites. [6] Northrop Grumman, a US defence company, built them. [6] They join 63 already in orbit from three earlier launches. [6] This first full round is meant to reach 126 satellites that pass data around and 28 that track missiles, and to start working for the US military in 2027. [6]

   Data satellites in orbit before this launch63 satellites

   Due to launch on 5 October21 satellites

   Data satellites planned in this round126 satellites

   Why it matters — The satellites fly 750 to 1,200 km up and talk to each other by laser. [6] The agency says that when this round is complete, 95% of Earth will be in view of at least two of them at any moment. [6] It plans 300 to 500 of these data satellites in all. [6]

4. 05

   Mars deltas point to one ocean, then lakes

   A team using a water tank at Nagasaki University in Japan grew small deltas, the fans of sand a river leaves where it meets still water. [7] They raised or lowered the water while the sand kept coming, and falling water built one kind of delta while rising water built another. [7] Matching those shapes to deltas seen on Mars, they date the falling-water kind to 3.8 to 3.2 billion years ago, near what may be an old shoreline. [7] The rising-water kind is much younger, from 2.1 billion to 100 million years old. [7]

   Why it matters — The authors say this fits one big ocean that drained away, followed by short-lived lakes in separate places. [7] Scientists still argue over whether Mars ever had an ocean, and the study, in the journal npj Space Exploration, adds one more line of evidence. [7]

5. 06

   Testing whether young Earth kept its own water

   Alisha Clark, a mineral physicist at the University of Colorado Boulder, fired the last shot of a years-long project on the Z machine in late August. [8] The Z machine, at Sandia National Laboratories in New Mexico, crushes samples with a shockwave to pressures like those deep inside giant planets. [8] Each shot takes a day to set up and costs about $250,000. [8] About 10% of shots go to basic research. Most of the machine's work still tests materials for US nuclear weapons. [8]

   Why it matters — The usual story says molten young Earth lost its water, and comets and asteroids brought new water later. [8] Clark's earlier tests found that water-filled glass, standing in for melted rock, gets easier to squeeze the harder it is pressed. [8] She thinks this could help melted rock hold on to water, which would mean much of Earth's water was inside it from the start and came out later through volcanoes. [8]

6. 07

   Mars beside the Moon, then in the Beehive

   Before dawn on 5 October, Mars sits just to the upper right of a thin crescent Moon in the east-northeast sky. [9] Mars is now about 245 million km from Earth and slowly getting brighter. [9] On the mornings of 10, 11 and 12 October it crosses the Beehive, a star cluster in the constellation Cancer where binoculars show about 100 stars. [9]

   Why it matters — The Beehive is easy to find with the naked eye from a dark place, and Galileo was the first to see it as separate stars, in 1610. [9] Mars then moves on into the constellation Leo on 31 October. [9]