ASTRONOMY - Red Sprite Lightning over the Czech Republic

 2022 September 12

Red Sprite Lightning over the Czech Republic
Image Credit & Copyright: Daniel Ščerba

Explanation: What are those red filaments in the sky? They are a rarely seen form of lightning confirmed only about 35 years ago: red sprites. Research has shown that following a powerful positive cloud-to-ground lightning strike, red sprites may start as 100-meter balls of ionized air that shoot down from about 80-km high at 10 percent the speed of light. They are quickly followed by a group of upward streaking ionized balls. The featured image was taken late last month from the Jeseniky Mountains in northern Moravia in the Czech Republic. The distance to the red sprites is about 200 kilometers. Red sprites take only a fraction of a second to occur and are best seen when powerful thunderstorms are visible from the side.

ASTRONOMY - Planets of the Solar System: Tilts and Spins

 2022 September 11

Planets of the Solar System: Tilts and Spins
Video Credit: NASA, Animation: James O'Donoghue (JAXA)

Explanation: How does your favorite planet spin? Does it spin rapidly around a nearly vertical axis, or horizontally, or backwards? The featured video animates NASA images of all eight planets in our Solar System to show them spinning side-by-side for an easy comparison. In the time-lapse video, a day on Earth -- one Earth rotation -- takes just a few seconds. Jupiter rotates the fastest, while Venus spins not only the slowest (can you see it?), but backwards. The inner rocky planets, across the top, most certainly underwent dramatic spin-altering collisions during the early days of the Solar System. The reasons why planets spin and tilt as they do remains a topic of research with much insight gained from modern computer modeling and the recent discovery and analysis of hundreds of exoplanets: planets orbiting other stars.

ASTRONOMY - Interstellar Voyager

 2022 September 9

Interstellar Voyager
Poster Illustration Credit: NASA, JPL-Caltech, Voyager

Explanation: Voyager 1 and Voyager 2 were launched in 1977 on a grand tour of the outer planets of the Solar System. They have become the longest operating and most distant spacecraft from Earth. Both have traveled beyond the heliosphere, the realm defined by the influence of the solar wind and the Sun's magnetic field. On the 45th year of their journey toward the stars Voyager 1 and 2 reached nearly 22 light-hours and 18 light-hours from the Sun respectively and remain the only spacecraft currently exploring interstellar space. Each spacecraft carries a 12-inch gold-plated copper disk with recordings of sounds, pictures and messages. The Golden Records are intended to communicate a story of life and culture on planet Earth, preserved in a medium that can survive an interstellar journey for a billion years.

ASTRONOMY - North America and the Pelican

 2022 September 8

North America and the Pelican
Image Credit & Copyright: Frank Sackenheim

Explanation: Fans of our fair planet might recognize the outlines of these cosmic clouds. On the left, bright emission outlined by dark, obscuring dust lanes seems to trace a continental shape, lending the popular name North America Nebula to the emission region cataloged as NGC 7000. To the right, just off the North America Nebula's east coast, is IC 5070, whose avian profile suggests the Pelican Nebula. The two bright nebulae are about 1,500 light-years away, part of the same large and complex star forming region, almost as nearby as the better-known Orion Nebula. At that distance, the 3 degree wide field of view would span 80 light-years. This careful cosmic portrait uses narrowband images combined to highlight the bright ionization fronts and the characteristic glow from atomic hydrogen, and oxygen gas. These nebulae can be seen with binoculars from a dark location. Look northeast of bright star Deneb in Cygnus the Swan, soaring high in the northern summer night sky.

ASTRONOMY - Tarantula Stars R136 from Webb

 2022 September 7

Tarantula Stars R136 from Webb
Images Credit & Copyright: NASA, ESA, CSA, STScI, Webb ERO Production Team

Explanation: Near the center of a nearby star-forming region lies a massive cluster containing some of the largest and hottest stars known. Collectively known as star cluster NGC 2070, these stars are part of the vast Tarantula Nebula and were captured in two kinds of infrared light by the new Webb Space Telescope. The main image shows the group of stars at NGC 2070's center -- known as R136 -- in near-infrared, light just a bit too red for humans to see. In contrast, the rollover image captures the cluster center in mid-infrared light, light closer to radio waves. Since R136's brightest stars emit more of their light in the near infrared, they are much more prominent on that image. This LMC cluster's massive stars emit particle winds and energetic light that are evaporating the gas cloud from which they formed. The Webb images, released yesterday, shows details of R136 and its surroundings that have never been seen before, details that are helping humanity to better understanding of how all stars are born, evolve and die.

ASTRONOMY - An Iridescent Pileus Cloud over China

 2022 September 6

An Iridescent Pileus Cloud over China
Image Credit & Copyright: Jiaqi Sun （孙嘉琪）

Explanation: Yes, but how many dark clouds have a multicolored lining? Pictured, behind this darker cloud, is a pileus iridescent cloud, a group of water droplets that have a uniformly similar size and so together diffract different colors of sunlight by different amounts. The featured image was taken last month in Pu'er, Yunnan Province, China. Also captured were unusual cloud ripples above the pileus cloud. The formation of a rare pileus cloud capping a common cumulus cloud is an indication that the lower cloud is expanding upward and might well develop into a storm.

ASTRONOMY - Sea and Sky Glows over the Oregon Coast

 2022 September 4

Sea and Sky Glows over the Oregon Coast
Image Credit & Copyright: Rudy Montoya

Explanation: Every step caused the sand to light up blue. That glow was bioluminescence -- a blue radiance that also lights the surf in this surreal scene captured in mid-2018 at Meyer's Creek Beach in Oregon, USA. Volcanic stacks dot the foreground sea, while a thin fog layer scatters light on the horizon. The rays of light spreading from the left horizon were created by car headlights on the Oregon Coast Highway (US 101), while the orange light on the right horizon emanates from a fishing boat. Visible far in the distance is the band of our Milky Way Galaxy, appearing to rise from a dark rocky outcrop. Sixteen images were added together to bring up the background Milky Way and to reduce noise.

METEO EXTREME - Un cyclone tropical anormal menacerait la Péninsule Ibérique et la France

Alors que la canicule a sévèrement frappé l’Europe occidentale ces dernières semaines, il n’y a pas que dans les terres que la température a fortement grimpé.

L’océan Atlantique a en effet été le théâtre d’un réchauffement significatif qui risque de ne pas être sans conséquence.

Ainsi, plusieurs experts et autres scientifiques tirent la sonnette d’alarme quant à l’éventualité d’assister à un phénomène naturel de grande ampleur provoqué par ce réchauffement.

C’est notamment le cas de Juan Gonzalez Aleman, météorologue au sein de l’Aemet (Agence espagnole de météorologie), qui affirme sur Twitter qu’un « ouragan » va se former à une « latitude inhabituelle » dans l'Atlantique nord et que celui-ci pourrait bien toucher la péninsule ibérique puis la France.

Le météorologue prévoit deux scénarios possibles. Le premier prédit que ce « cyclone tropical anormal » pourrait affecter l’Espagne. Une hypothèse confirmée par ailleurs par le centre National des Ouragans aux États-Unis. Quant au second, il mise sur un changement de trajectoire de l’ouragan qui cette fois remonterait vers le nord avec le risque de toucher la France.

Si l’expert reconnaît qu’il n’existe aucune certitude car « des processus complexes entrent en jeu », il estime néanmoins qu’il s’agit d’un « problème assez grave et suffisamment représentatif pour surveiller et être attentif ».

Démotivateur

ASTRONOMY - Sun and Moon and ISS

 2022 September 3

Sun and Moon and ISS
Image Credit & Copyright: Wang Letian (Eyes at Night), Jin Ma (Beijing Planetarium)

Explanation: On August 25 Sun and Moon could both be seen in planet Earth's daytime skies. And so could the International Space Station. The ISS crossed the disk of the waning crescent Moon as seen from Shunyi district, Beijing, China at about 11:02 am local time. Some 40 kilometers to the southwest, in Fengtai district, the ISS was seen to cross the Sun's disk too. The solar transit was observed only 29 seconds later. Both transits are compared in these panels, composed of processed and stacked video frames from the two locations. The coordinated captures were made with different equipment, but adjusted to show the Sun and Moon at the same scale. The ISS was at a calculated range of 435 kilometers for the lunar transit and 491 kilometers when passing in front of the Sun.

ASTRONOMY - M51: The Whirlpool Galaxy

2022 September 2

M51: The Whirlpool Galaxy
Image Credit & Copyright: Fabian Neyer

Explanation: Find the Big Dipper and follow the handle away from the dipper's bowl until you get to the last bright star. Then, just slide your telescope a little south and west and you'll come upon this stunning pair of interacting galaxies, the 51st entry in Charles Messier's famous catalog. Perhaps the original spiral nebula, the large galaxy with well defined spiral structure is also cataloged as NGC 5194. Its spiral arms and dust lanes clearly sweep in front of its companion galaxy (left), NGC 5195. The pair are about 31 million light-years distant and officially lie within the angular boundaries of the small constellation Canes Venatici. In direct telescopic views, M51 looks faint and fuzzy to the eye. But this remarkably deep image shows off details of the interacting galaxy's striking colors and galactic tidal debris. The image includes nearly 90 hours of narrowband data that also reveals a vast glowing cloud of reddish ionized hydrogen gas discovered in the M51 system.