Astronomy: space conquest and the latest news from the stars

[Christophe]

Astral self-flagelation?

[moinsdewatt]

Given the very low gravity field, it must be very gentle as a scourging.

[Christophe]

Not so sweet since it seems to me to be a vicious circle, right?

[Christophe]

Seriously?

[Christophe]

The density of space changes at the limits of the solar system:



To conclude:

Unexpected and unexplained (for the moment) detection of an increase in density in the interstellar medium by Voyager probes

(...)

However, the two Voyager 1 and 2 probes detected an increase in density beyond the heliopause, the border considered to be the boundary between the Solar System and the interstellar medium. Although astrophysicists do not yet know the cause, several hypotheses have been made.

(...)

The average electron density of the Milky Way's interstellar medium has been calculated to be about 0.037 particles per cubic centimeter. And the density of the plasma in the outer heliosphere is about 0.002 electrons per cubic centimeter. As Voyager probes passed beyond the heliopause, their Plasma Wave Science instruments detected the electron density of plasma through oscillations of the plasma.

Voyager 1 crossed the heliopause on August 25, 2012, at a distance of 121.6 astronomical units from Earth (121.6 times the distance between Earth and the Sun, or about 18.1 billion km). When it first measured the oscillations of the plasma after crossing the heliopause on October 23, 2013 at a distance of 122.6 astronomical units (18.3 billion km), Voyager 1 detected a plasma density of 0.055 electrons per centimeter cube.

Voyager 2 crossed the heliopause on November 5, 2018 at a distance of 119 astronomical units (17.8 billion km). It measured the oscillations of the plasma on January 30, 2019 at a distance of 119.7 astronomical units (17.9 billion km), finding a plasma density of 0.039 electrons per cubic centimeter, very close to the measurement of Voyager 1. And the two instruments reported an increase in density. After traveling another 20 astronomical units (2.9 billion km) through space, Voyager 1 reported an increase of about 0.13 electron per cubic centimeter

(...)

[moinsdewatt]

US probe Osiris-Rex will "kiss" an asteroid on Tuesday

AFP • 20 / 10 / 2020

After 12 years of preparations and four years of travel, the big day has arrived for the American probe Osiris-Rex: it will hit the asteroid Bennu on Tuesday in an attempt to collect a few tens of grams of dust, a high-precision operation at 330 million kilometers away from Earth.
......

Read https://www.boursorama.com/actualite-ec ... 7457e829c5

[moinsdewatt]

Osiris-Rex probe likely managed to collect asteroid fragments, NASA believes

AFP • 21 / 10 / 2020

The US space agency on Wednesday released the first images of the asteroid Bennu's soil sampling operation by the Osiris-Rex probe the day before, which show that the device may have succeeded in recovering grains or pebbles.

The probe touched the asteroid's ground for about 6 seconds to collect, using an arm, grains of sand and dust from Bennu's ground, lifted from the surface by a blast of compressed gas.

On the succession of photographs taken during the approach, we see the arm approaching the ground, then obviously breaking a large but apparently crumbly stone at the moment of contact, which is good news, said Dante Lauretta, responsible for the mission. , since that would have created fragments more easily recoverable by the arm.

Then the blast of nitrogen launched a cloud of dust and grains, according to the images - again good news.

"The conclusion, based on the images we have received so far, is that the sampling operation went very well, as well as expected," the scientist said.

The likelihood that materials have been collected "has greatly increased", he said.

The next few days will deliver the final verdict: first on the basis of photographs of the sample inside the probe, then with the exact measurement of mass, by a rotation operation of the probe on Saturday, with a report final expected Monday. The goal is at least 60 grams recovered.

The probe was not damaged on contacting the asteroid, the mechanism did trigger, and it was then able to move away at a safe distance.

"The Osiris-Rex mission went beyond all expectations," said NASA boss Jim Bridenstine, congratulating the teams.

The samples will then have to be brought back to Earth: the return is scheduled for September 2023.

https://www.boursorama.com/actualite-ec ... aae871d9e8

[Christophe]

It took them a long time ...

[moinsdewatt]

Delicate operation Tuesday to secure the cargo of the Osiris-Rex probe
AFP • 26 / 10 / 2020

https://www.boursorama.com/actualite-ec ... 9b5fb7e0b0

[moinsdewatt]

NASA's Perseverance rover is halfway between Earth and Mars

By Anne-Sophie Tassart the 28.10.2020

The Perseverance rover, transported in the Mars 2020 mission probe, is halfway between Earth and Mars, which it should reach on February 18, 2021.

https://www.sciencesetavenir.fr/espace/ ... min_148790