This is a repository for all cool scientific discussion and fascination. Scientific facts, theories, and overall cool scientific stuff that you'd like to share with others. Stuff that makes you smile and wonder at the amazing shit going on around us, that most people don't notice.
Post pictures, vidoes, stories, or links. Ask questions. Share science.
Originally Posted by Easy 6:
Sooo... has there been ANY news about the probe we sent into Jupiters atmosphere?
I was excited to hear about the amazing things they were expecting to find, like metals that simultaneously exist as a gas etc etc etc
ps - the turkeys circling the dead cat is... weird AF
It had an issue with it's helium reservoir. Which scared NASA into forcing it into an orbit much much further out than what they had anticipated. But fortunately, they planned for such a possible failure, and had a bunch of "backup" experiments they could run instead of the ones they'd planned for the shorter orbit.
I'll post some additional info when I have some time..
Originally Posted by Fish:
It had an issue with it's helium reservoir. Which scared NASA into forcing it into an orbit much much further out than what they had anticipated. But fortunately, they planned for such a possible failure, and had a bunch of "backup" experiments they could run instead of the ones they'd planned for the shorter orbit.
I'll post some additional info when I have some time..
I would appreciate that
But by "helium reservoir", they probably meant "the monolith"... [Reply]
NASA's Juno mission to Jupiter, which has been in orbit around the gas giant since July 4, 2016, will remain in its current 53-day orbit for the remainder of the mission. This will allow Juno to accomplish its science goals, while avoiding the risk of a previously-planned engine firing that would have reduced the spacecraft's orbital period to 14 days.
"Juno is healthy, its science instruments are fully operational, and the data and images we've received are nothing short of amazing," said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate in Washington. "The decision to forego the burn is the right thing to do—preserving a valuable asset so that Juno can continue its exciting journey of discovery."
Juno has successfully orbited Jupiter four times since arriving at the giant planet, with the most recent orbit completed on Feb. 2. Its next close flyby of Jupiter will be March 27.
The orbital period does not affect the quality of the science collected by Juno on each flyby, since the altitude over Jupiter will be the same at the time of closest approach. In fact, the longer orbit provides new opportunities that allow further exploration of the far reaches of space dominated by Jupiter's magnetic field, increasing the value of Juno's research.
During each orbit, Juno soars low over Jupiter's cloud tops—as close as about 2,600 miles (4,100 kilometers). During these flybys, Juno probes beneath the obscuring cloud cover and studies Jupiter's auroras to learn more about the planet's origins, structure, atmosphere and magnetosphere.
The original Juno flight plan envisioned the spacecraft looping around Jupiter twice in 53-day orbits, then reducing its orbital period to 14 days for the remainder of the mission. However, two helium check valves that are part of the plumbing for the spacecraft's main engine did not operate as expected when the propulsion system was pressurized in October. Telemetry from the spacecraft indicated that it took several minutes for the valves to open, while it took only a few seconds during past main engine firings.
"During a thorough review, we looked at multiple scenarios that would place Juno in a shorter-period orbit, but there was concern that another main engine burn could result in a less-than-desirable orbit," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. "The bottom line is a burn represented a risk to completion of Juno's science objectives."
Juno's larger 53-day orbit allows for "bonus science" that wasn't part of the original mission design. Juno will further explore the far reaches of the Jovian magnetosphere—the region of space dominated by Jupiter's magnetic field—including the far magnetotail, the southern magnetosphere, and the magnetospheric boundary region called the magnetopause. Understanding magnetospheres and how they interact with the solar wind are key science goals of NASA's Heliophysics Science Division.
"Another key advantage of the longer orbit is that Juno will spend less time within the strong radiation belts on each orbit," said Scott Bolton, Juno principal investigator from Southwest Research Institute in San Antonio. "This is significant because radiation has been the main life-limiting factor for Juno."
Juno will continue to operate within the current budget plan through July 2018, for a total of 12 science orbits. The team can then propose to extend the mission during the next science review cycle. The review process evaluates proposed mission extensions on the merit and value of previous and anticipated science returns.
The Juno science team continues to analyze returns from previous flybys. Revelations include that Jupiter's magnetic fields and aurora are bigger and more powerful than originally thought and that the belts and zones that give the gas giant's cloud top its distinctive look extend deep into the planet's interior. Peer-reviewed papers with more in-depth science results from Juno's first three flybys are expected to be published within the next few months. In addition, the mission's JunoCam—the first interplanetary outreach camera—is now being guided with assistance from the public. People can participate by voting on which features on Jupiter should be imaged during each flyby.
"Juno is providing spectacular results, and we are rewriting our ideas of how giant planets work," said Bolton. "The science will be just as spectacular as with our original plan."
The rise and fall of the ISS... in orbit, the station is constantly falling toward the earth. If not for the routine correction boosters, it would fall into the atmosphere and burn up. Fun thought for the astronauts aboard I'm sure...
This plot shows the orbital height of the ISS over the last year. Clearly visible are the re-boosts which suddenly increase the height, and the gradual decay in between. The height is averaged over one orbit, and the gradual decrease is caused by atmospheric drag. As can be seen from the plot, the rate of descent is not constant and this variation is caused by changes in the density of the tenuous outer atmosphere due mainly to solar activity.
So, the recent TRAPPIST-1 planet discovery? This is actually what we saw from Earth. Not to discredit the discovery or anything. There's an incredible amount behind the scenes and it's infinitely more complex than just a pic. But this is how they tracked the planet and determined their orbit and size.
That said, once the JWST get in the air, holy shit there's going to be another huge jump in clarity, distance, light pollution prevention, etc. [Reply]
Pest control and microbial disinfection protocols often utilize ultraviolet (UV) light. The reason is because UV light is extremely damaging to cells. Not only does it trigger the production of toxic compounds (such as reactive oxygen species), but it also causes weird structural changes in DNA (known as thymine dimers). The results are fatal.
UV light, however, is also dangerous to humans. So there is widespread interest in discovering light sources that can kill unwanted organisms while leaving humans unscathed. Farmers may be able to take advantage of the fact that fruit fly pupae are killed by blue light (wavelength = 467 nm), while public health officials should note that one species of mosquito is susceptible to violet light (wavelength = 417 nm).
These aren't the only "bugs" vulnerable to deadly visible light. Now, scientists from Singapore report in the journal Applied and Environmental Microbiology how violet light (wavelength = 405 nm) kills Salmonella in the refrigerator.
Causing about one million cases, Salmonella is the second most common source of domestically acquired foodborne illness in America, according to numbers from the CDC. Resulting in nearly 20,000 hospitalizations and roughly 400 deaths every year, the reduction of Salmonella in our food supply would save both lives and healthcare costs*.
From a distance of 4.5 cm (1.8 in.), the researchers shined violet LED bulbs on 18 different strains of Salmonella growing on Petri plates. As shown in the image on the right, some were nearly wiped out, while other strains managed to survive well enough. All of them, however, grew much less than they did when no violet light was shined on them.
The team then selected the single most light-sensitive and single most light-resistant strains for further analysis. Their experiments revealed that both strains were extensively injured by the 405 nm light. DNA was damaged, efflux pumps were inhibited, and glucose uptake was reduced. So why was one strain likelier to survive such an assault, while the other one died?
Subsequent analysis indicated that the cold temperature of the refrigerator and/or starvation conditions activated genes that help the hardier bacterium survive during times of stress; the frail bacterium didn't activate all of these genes. Essentially, inherent genetic differences may explain why some strains of Salmonella survive what other strains would find to be a lethal dose of violet light.
The team says that previous research it conducted showed that visible light of 405 nm (violet) and 460 nm (blue) can also kill Bacillus cereus, E. coli O157:H7, Listeria monocytogenes, Shigella sonnei, and Staphylococcus aureus, all of which cause food poisoning.
The present study has a few limitations. First, the researchers didn't examine how 405 nm light would work against Salmonella present in food samples, such as chicken. Second, they didn't determine how many light bulbs would need to be in a refrigerator in order to substantially reduce Salmonella contamination.
Still, if meat processing equipment and home refrigerators came equipped with little blue and violet lights, perhaps fewer of us would end up sick or in the hospital.
*Note: Worldwide, the numbers are much worse: Salmonella is blamed for 94 million infections and 155,000 deaths. [Reply]
