When two become one: 200 boffins contribute to first Ultima Thule paper
China adds to Beidou constellation while India preps radar-imaging satellite
Roundup While SpaceX twiddled its thumbs and NASA salivated at the prospect of a return to the Moon, last week China put another satellite into space and the New Horizons gang published its first batch of findings.
The Name's Ultima. Ultima Thule
Data keeps on dribbling down from the receding New Horizons spacecraft, and the team responsible for the mission has published a peer-reviewed science paper summarising the story so far.
The spacecraft hurtled past 2014 MU69 (aka Ultima Thule) on 1 January 2019, making it the farthest object explored by a probe to date.
It consists of two lobes – a large, flat one dubbed "Ultima" and a smaller, rounder blob nicknamed "Thule". At about 36km long, the planetesimal is a well-preserved relic from the formation of the solar system.
Scientists have puzzled over how the two lobes joined and, in the paper co-authored by 200 boffins, speculate that Ultima and Thule once orbited each other before gently coming together as the duo's momentum dissipated.
As for how that dissipation happened – aerodynamic forces from gas back in the day has been fingered, as has the possibility of the bodies ejecting other lobes to shed energy. However, boffins are more convinced that both lobes must have been tidally locked before the coming together.
The team has also been studying features on the surface of the object, with the largest depression being an 8km-wide depression nicknamed "Maryland crater". Other pockmarks could have been caused by sublimation of ice or other mystery processes.
Finally, Ultima Thule is also red. Really red. The team reckoned it is redder than Pluto and the reddest outer solar system object visited by a spacecraft. Intriguingly, this hue is thought to be caused by the modification of organic materials on the surface, with scientists spotting evidence of methanol and water ice.
The transmission of data from New Horizons is expected to carry on for at least another year – to summer 2020 – as the probe continues its mission. The spacecraft remains healthy, with fuel to spare, so a flyby of another Kuiper Belt object remains on the cards.
As long as promises not to gut other NASA missions on the altar of Moon landings by 2024 are kept.
China notches up seventh launch success for 2019
While SpaceX's Falcon 9 and its 60 satellites remain rooted to the Earth, China flung up another satellite for its Beidou navigation network last week.
The launch was the first of the Long March 3C variant in 2019 and the 17th success since the rocket made its debut in 2008. The 3C is effectively the three-stage, liquid-fuelled Long March 3A with a couple of boosters strapped to the side to increase the geostationary transfer orbit payload to 3,800kg.
Lift off was at 15:48 UTC on 17 May and the Long March 3C sent the satellite into a transfer orbit where the spacecraft will use its own engine to reach a geostationary orbit above the planet. Beidou is China's answer to the US GPS, the Russian GLONASS and the European Galileo navigation system. The launch follows April's Long March 3B, which sent up another Beidou satellite.
By 2020, the final Beidou fleet is expected to be 35 satellites strong.
India readies another rocket to put a spacecraft into orbit, not blow things up
India is preparing to launch RISAT-2B, a radar-imaging Earth observation satellite next week atop its snappily titled Polar Satellite Launch Vehicle (PSLV). The mission, the 48th for the rocket family and the third PSLV of 2019, will deposit the 615kg RISAT-2B in an orbit 557km above the surface at an inclination of 37 degrees.
ISRO plan to use the satellite during its anticipated five-year lifespan to keep an eye on agriculture, forestry and assist with disaster management. The launch will occur at 05:27 IST on 22 May from the First Launch Pad of the Satish Dhawan Space Centre.
This particular variant of the PSLV is the "Core Alone" incarnation, which dispenses with the strap-on boosters of its siblings. It'll be the 14th launch for this particular type, with the last having successfully deposited its payload into low earth orbit back in November 2018. ®