Denisova chassait les grands mammifères de la steppe



When NASA announced that the new Nancy Grace Roman Space Telescope will perform its science duties from a point in space known as Lagrange 2, many observers noted that the space agency’s current state-of-the-art space observatory, the James Webb Space Telescope, shares this same orbital location.
Due to the extremely sensitive nature of both satellites and their sensors, and the irreplaceable scientific value they will provide in the future, it might seem natural to wonder whether these two space observatories are at risk of a deep-space collision.
Fortunately, that’s a very unlikely prospect, and here’s a look at all the space separating Roman and Webb—and how NASA will ensure the two observatories remain safely apart.
Many scientific satellites reside a little over 200 miles above Earth in an orbital plane called Low Earth Orbit (LEO). This proximity enables communication with Earth and offers the potential for future servicing missions.
For example, NASA’s groundbreaking Hubble Space Telescope orbits LEO at about 300 miles above Earth. This proximity enabled servicing missions that have kept Hubble delivering valuable scientific data for over three and a half decades since its 1990 launch. Still, LEO also limits which missions Hubble can undertake.
More recently, NASA launched JWST. However, unlike Hubble, Webb rocketed roughly one million miles from Earth before arriving at Lagrange 2. According to a NASA fact sheet detailing the Roman Space Telescope’s mission, this location offers several benefits over LEO.
“At L2, the gravity of the Sun and Earth, together with an object’s motion around the Sun, let it stay lined up with Earth as they orbit,” NASA explains, “allowing Roman to have a relatively steady orbit without using much fuel.”
NASA also notes that heat from Earth, the Sun, and the Moon has less impact on infrared telescopes designed to “see” heat. L2 also offers JWST and Roman, “a constant, unobstructed view of a wide swath of the sky.”
“Earth won’t block much of Roman’s view since it will be so distant,” NASA explains.
Instead of sitting still at the heart of L2, NASA notes that Webb “traces out a large orbit around the actual L2 point.” For comparison, the space agency noted that JWST’s orbit around L2 is “much larger than the Moon’s orbit around Earth.”
Like Webb, the Nancy Grace Roman Space Telescope is also destined for L2. The new space telescope will also trace out an orbit around L2 rather than remaining comparatively stationary.
Because of the wide orbits of both spacecraft and the efforts of the mission’s controllers, NASA said the two valuable space telescopes “will easily be kept far apart.”
Like previous NASA missions, Roman will have a primary lifetime and a backup plan if the observatory remains viable after the first mission ends. For Roman, both the primary and secondary missions are slated for five years, bringing the observatory’s planned potential lifetime up to a possible ten years.
Notably, several NASA missions have continued to deliver scientific data well beyond their planned primary and secondary missions. Perhaps the most famous example is Voyager 1. Launched in 1977, the interplanetary mission has since left the solar system and continues to return data from beyond the heliopause, an area of deep space over 14 billion miles from Earth.
When discussing what obstacles may result in a shorter mission profile, NASA said that “fuel is expected to be the mission’s life-limiting resource.”
“While NASA does not currently have an ability to service observatories at L2, Roman is designed to be refuellable,” they added.
Christopher Plain is a Science Fiction and Fantasy novelist and has spent the last six years as Associate News Editor and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him at christopher@thedebrief.org.


Arctic communications award will fund an expansion of Telesat’s Lightspeed, taking the planned LEO network to 225 spacecraft
The post Telesat lands $1.63 billion Canadian defense contract appeared first on SpaceNews.




A Amazon solicitou à Comissão Federal de Comunicações (Federal Communications Commission, ou FCC) dos Estados Unidos uma licença para operar uma nova rede de 5.105 satélites destinada a fornecer serviços para dispositivos celulares, com planos de iniciar os lançamentos em 2028.
A iniciativa ocorre meses depois de a Amazon ter adquirido as operações de satélite da Globalstar, empresa que viabiliza os recursos via satélite do iPhone e do Apple Watch Ultra 3.

À época da notícia, inclusive, a Apple e a Amazon firmaram um acordo pelo qual a Globalstar operará em conjunto com a rede de satélites Leo 1Low Earth orbit, ou órbita terrestre baixa. da Amazon; de modo que ambas as redes sustentarão futuros serviços via satélite para a Maçã.
A Amazon Leo já anunciou um acordo com a Apple para viabilizar serviços via satélite para modelos compatíveis de iPhone e Apple Watch — incluindo SOS de Emergência via satélite, Mensagens, Buscar e Assistência Rodoviária via satélite — e para colaborar com a Apple em futuros serviços via satélite utilizando a rede expandida.
A Amazon planeja implantar cinco camadas orbitais projetadas para cobrir diferentes regiões do planeta. Três delas atenderão áreas densamente povoadas, enquanto as outras estenderão o serviço às regiões polares.
via MacRumors



NASA’s Juno mission scientists have reported the first successful temperature measurements below the surface of Jupiter’s moon Io, including indications of significant heating within the moon’s shallow subsurface.
Collected during a pair of close flybys of the Solar System’s most volcanically active world, the Juno mission measurements were described as a complete “surprise” since the instrument was designed for a different purpose.
“[The readings] break new observational ground for both fiery and icy worlds beyond our planet,” the team said.
Due to the extreme gravitational pull of its host planet, Jupiter, Io is repeatedly stretched and pulled as its slightly elliptical orbit carries it around the massive gas giant. This repeated motion generates a tremendous amount of heat, which the scientists note is “many times greater” than the same type of heat generated on Earth.
However, a detailed understanding of this process has remained elusive, as the only data on the moon’s inner heat came from infrared telescope observations. The team notes this data is limited to the temperature of Io’s upper rocky surface layer.
Conversely, Juno is equipped with an instrument called the Microwave Radiometer (MWR). According to the team’s statement announcing the successful subsurface temperature detection, Juno’s Microwave Radiometer was custom designed by Scott Bolton, the mission’s principal investigator at Southwest Research Institute in San Antonio and a co-author of the study detailing the team’s findings, to “peer beneath Jupiter’s top clouds” for a closer look at the gas giant’s complex atmosphere.
“The MWR’s six microwave antennas serve as a single instrument, simultaneously detecting microwaves at a wide range of wavelengths, from about half an inch to 20 inches (1.3 to 51 centimeters),” the team explains.
Bolton said the team’s novel approach allowed the instrument to observe wavelengths from different depths, “providing a new way to characterize the deep atmosphere of giant planets and the subsurface crusts of icy and rocky moons.” This included observations of Jupiter’s other ‘Galilean’ moons, Ganymede and Europa.
“At Ganymede and Europa, we explored tens of miles below the surface, assuming their ice shells were mostly pure water,” the mission scientists explained.
However, Bolton added, using the instrument to successfully probe into Io’s volcanic rock “was an unexpected discovery.”

The feat was accomplished during a pair of flybys on December 30, 2023, and February 3, 2024, where Juno came within roughly 930 miles (1,500 km) of Io’s surface. Shannon Brown, the paper’s lead author at NASA’s Jet Propulsion Laboratory in Southern California, said that during these flybys the MWR instrument measured the moon’s thermal emission “at depths ranging from a few inches down to tens of feet.”
“Everywhere we looked, we found the temperature rising by more than 40 degrees Fahrenheit just several feet into the surface — a gradient far steeper than solar heating alone can explain,” Brown said.

Although more information is likely needed to make a conclusive determination, the team said that the data suggests two possible explanations for the readings. The first option is heat rising steadily through what the team termed a “conductive crust.”
“While this background heat flow — measured at 1 to 3 watts per square meter — is relatively gentle on a local scale (roughly equivalent to a small nightlight glowing under every square yard), across the entire moon it represents a release of energy up to 30 times Earth’s average,” they explained.
Another possibility proposed by the joint research team suggested that the heat signal detected by Juno’s MWR could be coming from cooling lava flows covered by 30 to 35 feet (9 to 11 meters) of solidified crust that cover approximately 10% of Io’s surface “at any given time.”
When discussing the implications of the team’s findings, Bolton said the “surprising” ability to see below Io’s surface “has important implications for studying Earth’s volcanoes.” He also noted that if scientists used a similar instrument to measure areas on Earth near volcanoes, they might see a similar heat signature in the planet’s subsurface temperature gradient, “providing new information on how terrestrial volcanoes work.”
“Io provides a unique window into learning how tidal heating works throughout the cosmos, a fundamental process that provides energy and heat to worlds that are far from their parent star,” Bolton explained. “This process can not only create the most volcanic body in the solar system, in the case of Io, but also fuels the subsurface oceans on the moons of giant planets, such as Europa and Ganymede.”
“Up until this point, we could only observe the heat escaping at the surface or through eruptions,” the mission scientists added. “Now we can characterize how the heat is moving from the interior toward the surface.”
NASA has additional information about Juno available at the mission’s official webpage.
Christopher Plain is a Science Fiction and Fantasy novelist and has spent the last six years as Associate News Editor and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him at christopher@thedebrief.org.
New navigation satellites in low-Earth orbit could provide 100 times stronger signal strength compared to GPS and other global navigation satellite systems operating from higher orbital altitudes—enabling greater location accuracy within dense cities, under thick foliage, and even inside buildings. Such signals would also likely prove more resilient to interference at a time when commercial flights, maritime shipping, and even various smartphone apps face increasingly widespread disruption from GPS jamming.
That vision may start to take shape when the first six production satellites of California-based Xona Space Systems are scheduled to launch in October 2026, with early service starting in 2027. Once the full constellation of 258 Pulsar satellites has been launched in the following years, Xona claims that customers will be able to accurately pinpoint their locations anywhere on Earth to within several centimeters.
“That added power means that we can get into that indoor environment that GPS can't get to today,” Adrien Perkins, co-founder and VP of engineering at Xona Space Systems, told Ars. “Our higher power allows you to get into those jamming environments a lot further than you would with GPS by itself.”


© Xona Space Systems
New navigation satellites in low-Earth orbit could provide 100 times stronger signal strength compared to GPS and other global navigation satellite systems operating from higher orbital altitudes—enabling greater location accuracy within dense cities, under thick foliage, and even inside buildings. Such signals would also likely prove more resilient to interference at a time when commercial flights, maritime shipping, and even various smartphone apps face increasingly widespread disruption from GPS jamming.
That vision may start to take shape when the first six production satellites of California-based Xona Space Systems are scheduled to launch in October 2026, with early service starting in 2027. Once the full constellation of 258 Pulsar satellites has been launched in the following years, Xona claims that customers will be able to accurately pinpoint their locations anywhere on Earth to within several centimeters.
“That added power means that we can get into that indoor environment that GPS can't get to today,” Adrien Perkins, co-founder and VP of engineering at Xona Space Systems, told Ars. “Our higher power allows you to get into those jamming environments a lot further than you would with GPS by itself.”


© Xona Space Systems
New navigation satellites in low-Earth orbit could provide 100 times stronger signal strength compared to GPS and other global navigation satellite systems operating from higher orbital altitudes—enabling greater location accuracy within dense cities, under thick foliage, and even inside buildings. Such signals would also likely prove more resilient to interference at a time when commercial flights, maritime shipping, and even various smartphone apps face increasingly widespread disruption from GPS jamming.
That vision may start to take shape when the first six production satellites of California-based Xona Space Systems are scheduled to launch in October 2026, with early service starting in 2027. Once the full constellation of 258 Pulsar satellites has been launched in the following years, Xona claims that customers will be able to accurately pinpoint their locations anywhere on Earth to within several centimeters.
“That added power means that we can get into that indoor environment that GPS can't get to today,” Adrien Perkins, co-founder and VP of engineering at Xona Space Systems, told Ars. “Our higher power allows you to get into those jamming environments a lot further than you would with GPS by itself.”


© Xona Space Systems

The final flight of United Launch Alliance's Atlas V rocket is still several years off, but an important era for the once-dominant launch company came to a close last week.
The final flight of an Atlas V for the Amazon Leo broadband constellation lifted off from Cape Canaveral Space Force Station in Florida at 12:30 am EDT (04:30 UTC) last Thursday, sending 29 satellites to orbit to move the network closer to providing initial services.
All 29 spacecraft deployed from the Atlas V rocket less than an hour after launch. They will use onboard propulsion to raise their orbits from an altitude of approximately 289 miles (465 kilometers) to their final operating positions at 392 miles (630 kilometers) above the Earth.


© United Launch Alliance
Marcando o oitavo voo consecutivo realizado com sucesso, o foguetão Ariane 6 colocou em órbita 36 satélites da constelação Leo da Amazon, aproveitando para bater o recorde europeu do voo mais “poderoso” de sempre.
The post Ariane 6 dá “boleia” a 36 satélites da Amazon e bate recorde europeu na capacidade de lançamento appeared first on Tek Notícias.

An Ariane 6 with upgraded solid rocket boosters successfully launched three dozen Amazon Leo satellites June 17 as ESA weighs options for increasing the vehicle’s launch rate.
The post Upgraded Ariane 6 launches Amazon Leo satellites appeared first on SpaceNews.
Amazon now has hundreds of flight-ready satellites standing idle in Florida, waiting to join the company's low-Earth orbit Internet constellation, an Amazon official said Tuesday.
"They're built, and sitting in a payload processing facility waiting for trips to orbit," said Steve Metayer, vice president of Amazon Leo Production Operations, during a teleconference with reporters. "And we're currently manufacturing several satellites a day."
Metayer spoke on the eve of the company's next mission, during which an Ariane 64 rocket will launch three dozen Amazon Leo satellites into orbit from a spaceport in French Guiana. Liftoff is targeted for 7:53 am ET (11:53 UTC) on Wednesday.


© Amazon