{"id":19112,"date":"2019-06-26T14:33:35","date_gmt":"2019-06-26T18:33:35","guid":{"rendered":"http:\/\/hobbyspace.com\/Blog\/?p=19112"},"modified":"2019-06-26T14:33:35","modified_gmt":"2019-06-26T18:33:35","slug":"space-sciences-roundup-june-26-2019","status":"publish","type":"post","link":"https:\/\/hobbyspace.com\/Blog\/?p=19112","title":{"rendered":"Space sciences roundup – June.26.2019"},"content":{"rendered":"

A sampling of recent articles, videos, and images from space-related science news items:<\/p>\n

Asteroids<\/strong>:<\/p>\n

** NASA’s OSIRIS-REx probe<\/a> gets up close to asteroid Bennu<\/a><\/strong> : OSIRIS-REx Breaks Another Orbit Record | NASA<\/a><\/p>\n

On June 12, NASA\u2019s OSIRIS-REx spacecraft performed another significant navigation maneuver\u2014breaking its own world record for the closest orbit of a planetary body by a spacecraft.<\/em><\/p>\n

The maneuver began the mission\u2019s new phase, known as Orbital B, and placed the spacecraft in an orbit 680 meters (2,231 feet) above the surface of asteroid<\/a> Bennu. The previous record\u2014also set by the OSIRIS-REx spacecraft\u2014was approximately 1.3 kilometers (0.8 miles) above the surface.<\/em><\/p>\n

Upon arrival at Bennu<\/a>, the team observed particles ejecting into space from the asteroid’s surface. To better understand why this is occurring, the first two weeks of Orbital B will be devoted to observing these events by taking frequent images of the asteroid’s horizon. For the remaining five weeks, the spacecraft will map the entire asteroid using most of its onboard science instruments: the OSIRIS-REx Laser Altimeter (OLA) will produce a full terrain map; PolyCam will form a high-resolution, global image mosaic; and the OSIRIS-REx Thermal Emission Spectrometer (OTES) and the REgolith X-ray Imaging Spectrometer (REXIS) will produce global maps in the infrared and X-ray bands. All of these measurements are essential for selecting the best sample collection site on Bennu\u2019s surface.<\/em><\/p>\n

Data from these surface studies will be used to find the optimum spot to set down and take a sample to take back to Earth.<\/p>\n

The OSIRIS-REx spacecraft is on a seven-year journey to study the asteroid Bennu and return a sample from its surface to Earth. This sample of a primitive asteroid will help scientists understand the formation of the Solar System over 4.5 billion years ago. Sample collection is scheduled for summer of 2020, and the spacecraft will deliver the sample to Earth in September 2023.<\/em><\/p>\n

\"An<\/a>
“On Jun. 12, 2019, NASA’s OSIRIS-REx spacecraft went into orbit around asteroid Bennu for a second time \u2014 breaking its own record for the closest orbit of a planetary body by any spacecraft.” Artwork credits: University of Arizona
<\/em><\/figcaption><\/figure>\n

** Japan’s Hayabusa2<\/a> probe may touch down on asteroid Ryugu<\/strong> again: Approach to the 2nd touchdown \u2013 Part 1: observations near the touchdown point – JAXA Hayabusa2 project<\/a><\/p>\n

Our first touchdown took place this year on February 22. Then as a new challenge for the Hayabusa2 Project, we succeeded in creating an artificial crater using the Small Carry-on Impactor (SCI) on April 5. The last big operation left at asteroid Ryugu is the collection of subsurface material exposed with the creation of the artificial crater. In order to collect this material, we need a second touchdown for which the project has been steadily preparing. At this point, it has not yet been decided whether or not to go ahead with a second touchdown, but here we will introduce our preparations in the \u201cApproach to the second touchdown\u201d.<\/em><\/p>\n

After the operation to form the artificial crater, the spacecraft descended a total of four times above or near the crater site. These descent operations allowed us to obtain detailed data of the region near the artificial crater. In addition, we succeeded in dropping a target marker in the area close to the artificial crater on May 30. Combined, these operations mean that the situation around the artificial crater is now well understood.<\/em><\/p>\n

The rocky surface, however, makes it difficult to find a safe spot to set down.<\/p>\n

As you can see in [the figure below], asteroid Ryugu is covered with boulders. If we go for a second touchdown, we need to aim for a point close to the target marker which has no obstacles. The project is currently examining this area in detail.<\/em><\/p>\n

\"Image<\/a>
“Image taken on June 13, 2019 during the operation PPTD-TM1B. This is a composite of 28 images taken at 7 second intervals starting from 10:58 JST (upper left) to 11:01 (lower right) using the Optical Navigation Camera \u2013 Telescopic (ONC-T). The image altitude is about 52m at the start and 108m at the end. The white point in the upper-left center is the target marker. You can see that detailed images have been acquired continuously from the target marker to the edge of the artificial crater, located in the lower-right of the image. (Image credit \u203b: JAXA, Chiba Institute of Technology, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Meiji University, University of Aizu, AIST.) “<\/em><\/figcaption><\/figure>\n

The Sun<\/strong>:<\/p>\n

** Lunar regolith reveals secrets of the early sun<\/strong>: Moon Samples Help Scientists Study Ancient Sun | NASA<\/a><\/p>\n

Saxena incorporated the mathematical relationship between a star\u2019s rotation rate and its flare activity. This insight was derived by scientists who studied the activity of thousands of stars discovered by NASA\u2019s Kepler space telescope: The faster a star spins, they found, the more violent its ejections. \u201cAs you learn about other stars and planets, especially stars like our Sun, you start to get a bigger picture of how the Sun evolved over time,\u201d Saxena said.\u00a0\u00a0<\/em><\/p>\n

Using sophisticated computer models, Saxena, Killen and colleagues think they may have finally solved both mysteries. Their computer simulations, which they described on May 3<\/a> in the The Astrophysical Journal Letters, show that the early Sun rotated slower than 50% of baby stars. According to their estimates, within its first billion years, the Sun took at least 9 to 10 days to complete one rotation.\u00a0\u00a0<\/em><\/p>\n

They determined this by simulating the evolution of our solar system under a slow, medium, and then a fast-rotating star. And they found that just one version \u2014 the slow-rotating star \u2014 was able to blast the right amount of charged particles into the Moon\u2019s surface to knock enough sodium and potassium into space over time to leave the amounts we see in Moon rocks today.\u00a0\u00a0\u00a0<\/em><\/p>\n

\u201cSpace weather was probably one of the major influences for how all the planets of the solar system evolved,\u201d Saxena said, \u201cso any study of habitability of planets needs to consider it.\u201d\u00a0<\/em><\/p>\n

Jupiter<\/strong>:<\/p>\n

**\u00a0 More wonderful views of Jupiter<\/strong> created by citizen scientists from Juno’s raw imagery: Tumultuous Clouds of Jupiter | Mission Juno\/Kevin M. Gill<\/a><\/p>\n

This stunning compilation image of Jupiter\u2019s stormy northern hemisphere was captured by NASA\u2019s Juno spacecraft as it performed a close pass of the gas giant planet. Some bright-white clouds can be seen popping up to high altitudes on the right side of Jupiter\u2019s disk. (The Juno team frequently refers to clouds like these as \u201cpop-up\u201d clouds in image captions.)<\/em><\/p>\n

Juno took the four images used to produce this color-enhanced view on May 29, 2019, between 12:52 a.m. PDT (3:52 a.m. EDT) and 1:03 a.m. PDT (4:03 a.m. EDT), as the spacecraft performed its 20th science pass of Jupiter. At the time the images were taken, the spacecraft was between 11,600 miles (18,600 kilometers) and 5,400 miles (8,600 kilometers) above Jupiter’s cloud tops, above a northern latitude spanning from about 59 to 34 degrees.<\/em><\/p>\n

Citizen scientist Kevin M. Gill created this image using data from the spacecraft’s JunoCam imager.<\/em><\/p>\n

\"Tumultuous<\/a>
“Tumultuous Clouds of Jupiter” – Credits NASA\/JPL-Caltech\/SwRI\/MSSS with image processing by Kevin M. Gill.<\/em><\/figcaption><\/figure>\n

Gill also made this overflight of Jupiter’s Great Red Spot<\/a>:<\/p>\n