** University of Washington physics professor emeritus Dr. John Cramer talked with David Livingston this week about interstellar propulsion schemes, wormholes for getting around the universe, connecting quantum mechanics and general relativity, and many other fun topics in a manner that a non-scientist can follow: The Space Show – Mon, 06/25/2018 – 14:00
** The latest episode of the Talking Space Podcast covered several topics including Opportunity rover enduring the massive dust storm on Mars, the SpaceX CRS-15 cargo mission to the ISS, and recent launches by China, Japan, and Russa : Episode 1005: #SaveOppy?
There’s a serious Global Dust Storm happening right now on Mars. Several regional storms have kicked up a tremendous amount of dust into the skies, blocking out the sun and jeopardizing the Opportunity rover’s safety. But despite the threat, this is a great chance to do some science on Mars weather. Jake is joined by Space Science Institute’s Mark Lemmon to discuss these storms formation and what we’re learning from them.
The world’s first 48-hour webcast about asteroids and their place in space will begin at 12:00 CEST, on Friday, 29 June 2018. Kicking off this exciting event, physicist, science advocate and former rock star Brian Cox will host the first 6-hour segment live from Luxembourg.
Brian will be joined by asteroid scientists, astronauts, rock stars and experts from around the world all in the name of Asteroid Day – the annual UN-endorsed global campaign to raise awareness about asteroids, and the risks and opportunities that they bring.
Asteroid Day takes place each year on 30 June, commemorating the 1908 Tunguska airburst over Siberia, the biggest impact event in recorded history. Since its inception, ESA has long supported the Asteroid Day initiative and plays a leading role in the global hunt for risky near-Earth objects that might one day cross our path.
** The Society has also opened a Kickstarter campaign called Kick Asteroid!
The Planetary Society is excited to partner with space artist and designer, Thomas Romer, and backers around the world to create Kick Asteroid—a colorful graphic poster that will illustrate the effect of past catastrophic impacts, and methods to deflect future asteroid threats. Compelling and scientifically accurate art will be created for posters and other “merch” that backers can use in their everyday lives to spread the word about planetary defense.
Asteroid and comet impacts, while not common, are very real threats. By backing this project, you can help spread the word about asteroid defense. You will be doing your part to protect the people of Earth from a devastating impact.
On June 27, 2018, JAXA operated Hayabusa2 chemical propulsion thrusters for the spacecraft’s orbit control.*
The confirmation of the Hayabusa2 rendezvous made at 9:35 a.m. (Japan Standard Time, JST) is based on the following data analyses;
・The thruster operation of Hayabusa2 occurred nominally
・The distance between Hayabusa2 and Ryugu is approximately 20 kilometers
・Hayabusa2 is able to maintain a constant distance to asteroid Ryugu
・The status of Hayabusa2 is normal
The probe will spend a year and half studying the diamond shaped asteroid and four small landers will be deployed onto the surface. In addition, the probe will grab a sample of the surface and return it to earth in December 2020.
This image captures swirling cloud belts and tumultuous vortices within Jupiter’s northern hemisphere.
NASA’s Juno spacecraft took this color-enhanced image at 10:23 p.m. PDT on May 23, 2018 (1:23 a.m. EDT on May 24), as the spacecraft performed its 13th close flyby of Jupiter. At the time, Juno was about 9,600 miles (15,500 kilometers) from the planet’s cloud tops, above a northern latitude of 56 degrees.
The region seen here is somewhat chaotic and turbulent, given the various swirling cloud formations. In general, the darker cloud material is deeper in Jupiter’s atmosphere, while bright cloud material is high. The bright clouds are most likely ammonia or ammonia and water, mixed with a sprinkling of unknown chemical ingredients.
A bright oval at bottom center stands out in the scene. This feature appears uniformly white in ground-based telescope observations. However, with JunoCam we can observe the fine-scale structure within this weather system, including additional structures within it. There is not significant motion apparent in the interior of this feature; like the Great Red Spot, its winds probably slows down greatly toward the center.
Citizen scientists Gerald Eichstädt and Seán Doran created this image using data from the spacecraft’s JunoCam imager.
This image captures the intensity of the jets and vortices in Jupiter’s North North Temperate Belt.
NASA’s Juno spacecraft took this color-enhanced image at 10:31 p.m. PDT on May 23, 2018 (1:31 a.m. EDT on May 24), as Juno performed its 13th close flyby of Jupiter. At the time, the spacecraft was about 4,900 miles (7,900 kilometers) from the tops of the clouds of the gas giant planet at a northern latitude of about 41 degrees. The view is oriented with south on Jupiter toward upper left and north toward lower right.
The North North Temperate Belt is the prominent reddish-orange band left of center. It rotates in the same direction as the planet and is predominantly cyclonic, which in the northern hemisphere means its features spin in a counter-clockwise direction. Within the belt are two gray-colored anticyclones.
To the left of the belt is a brighter band (the North North Temperate Zone) with high clouds whose vertical relief is accentuated by the low angle of sunlight near the terminator. These clouds are likely made of ammonia-ice crystals, or possibly a combination of ammonia ice and water. Although the region as a whole appears chaotic, there is an alternating pattern of rotating, lighter-colored features on the zone’s north and south sides.
Scientists think the large-scale dark regions are places where the clouds are deeper, based on infrared observations made at the same time by Juno’s JIRAM experiment and Earth-based supporting observations. Those observations show warmer, and thus deeper, thermal emission from these regions.
To the right of the bright zone, and farther north on the planet, Jupiter’s striking banded structure becomes less evident and a region of individual cyclones can be seen, interspersed with smaller, darker anticyclones.
Citizen scientist Kevin M. Gill created this image using data from the spacecraft’s JunoCam imager.
`Oumuamua, the first interstellar object discovered in the Solar System, is moving away from the Sun faster than expected. This anomalous behaviour was detected using the NASA/ESA Hubble Space Telescope in cooperation with ground-based telescopes. The new results suggest that `Oumuamua is most likely a comet and not an asteroid. The discovery appears in the journal Nature.
`Oumuamua — the first interstellar object discovered within our Solar System — has been the subject of intense scrutiny since its discovery in October 2017 . Now, by combining data from the NASA/ESA Hubble Space Telescope, the Canada-France-Hawaii Telescope, ESO’s Very Large Telescope and the Gemini South Telescope, an international team of astronomers has found that the object is moving faster than predicted. The measured gain in speed is tiny and `Oumuamua is still slowing down because of the pull of the Sun — just not as fast as predicted by celestial mechanics.
The team, led by Marco Micheli (European Space Agency) explored several scenarios to explain the faster-than-predicted speed of this peculiar interstellar visitor. The most likely explanation is that `Oumuamua is venting material from its surface due to solar heating — a behaviour known as outgassing. The thrust from this ejected material is thought to provide the small but steady push that is sending `Oumuamua hurtling out of the Solar System faster than expected — as of 1 June, it is travelling with about 114 000 kilometres per hour.
Such outgassing is a typical behaviour for comets and contradicts the previous classification of `Oumuamua as an interstellar asteroid.
“We think this is a tiny, weird comet,” comments Marco Micheli. “We can see in the data that its boost is getting smaller the farther away it travels from the Sun, which is typical for comets.”
Usually, when comets are warmed by the Sun they eject dust and gas, which form a cloud of material — called a coma — around them, as well as the characteristic tail. However, the research team could not detect any visual evidence of outgassing.
“We did not see any dust, coma, or tail, which is unusual,” explains co-author Karen Meech (University of Hawaii, USA) who led the discovery team’s characterisation of `Oumuamua in 2017. “We think that ‘Oumuamua may vent unusually large, coarse dust grains.”
The team speculated that perhaps the small dust grains adorning the surface of most comets eroded during `Oumuamua’s journey through interstellar space, with only larger dust grains remaining. A cloud of these larger particles would not be bright enough to be detected by Hubble.
Not only is `Oumuamua’s hypothesised outgassing an unsolved mystery, but also its interstellar origin. The team originally performed the new observations on `Oumuamua to exactly determine its path which would have probably allowed it to trace the object back to its parent star system. The new results means it will be more challenging to obtain this information.
“The true nature of this enigmatic interstellar nomad may remain a mystery,” concludes team member Olivier Hainaut (European Southern Observatory, Germany). “`Oumuamua’s recently-detected gain in speed makes it more difficult to be able to trace the path it took from its extrasolar home star.”
`Oumuamua, pronounced “oh-MOO-ah-MOO-ah”, was first discovered using the Pan-STARRS telescope at the Haleakala Observatory, Hawaii. Its name means “a messenger from afar, arriving first” in Hawaiian, and reflects its nature as the first known object of interstellar origin to have entered the Solar System.
 The team tested several hypotheses to explain the unexpected change in speed. They analysed whether solar radiation pressure, the Yarkovsky effect, or friction-like effects could explain the observations. It was also checked whether the gain in speed could have been caused by an impulse event (such as a collision), by `Oumuamua being a binary object or by `Oumuamua being a magnetised object. Also, the unlikely theory that `Oumuamua is an interstellar spaceship was rejected: the smooth and continuous change in speed is not typical for thrusters and the object is tumbling on all three axes, speaking against it being an artificial object.