James Webb telescope got attached to its spacecraft for the first time. I don't think I've anticipated the launch of anything this much.
Good question and one that is often not talked about. There are two types of days. A sidereal day and a solar day. A sidereal day measures the amount of time for the Earth to rotate to face the same direction relative to the fixed stars. This does not factor in the earth's circular orbital motion around the sun. A solar day is the time it takes for the Earth to rotate about its axis, to where the Sun appears in the same position in the sky. 23 hours 56 minutes and 4 seconds later and the Earth has rotated 360 degrees. However, it has also moved ~1 degree around the sun in its orbit. Therefore it has to turn about 1 extra degree to have the same point on Earth facing the Sun again, and that's what takes the day up to 24 hours. Spoiler: ELI5 A sidereal day is the amount of time it takes the earth to rotate 360 degrees around its axis. During that time, it has traveled along its orbit, and has to rotate about 4 minutes longer to return to its same position facing to the sun. That is a solar day. The average solar day varies throughout the year, but it has a standard average of 24 hours.
Side note, the general population uses solar time for timekeeping, while astronomers mostly use sidereal time to help aim their telescopes
Venus rotates so slowly, at first I didn't even realize it was actually moving in that GIF. Do we know why it rotates that slow?
China's Lunar Rover Finds a 'Gel-Like' Substance on The Far Side of The Moon Spoiler BY MICHELLE STARR SEPTEMBER 02, 2019 Chinese lunar rover Yutu-2 has rolled over a strange mystery on the far side of the Moon. At the bottom of a small, recent impact crater, the rover found a shiny unknown substance the Chinese space agency described as a "gel with a mysterious lustre". Although Chinese scientists have not yet revealed what it might be, the best guess from external scientists, according to Space.com, is that the material is glass that formed in the heat of the impact that left the crater. On July 28 - three days after the start of the two-week lunar day - the Yutu-2 science team at the Beijing Aerospace Control Center were preparing to power down the rover for a 'midday nap', a process that prevents the delicate machinery from overheating when the Sun is directly overhead. But team member Yu Tianyi noticed something unusual in the crater while checking a panorama photographed by Yutu-2. So the researchers kept the rover awake just a little bit longer, rolling it over to the crater for a better look. There, they found a glistening substance. According to the rover's drive diary, this material differed from the surrounding regolith in shape, colour and texture. (Sadly, they have released no photographs of it just yet, but you can see the crater itself in the images here.) This photo shows the scale of the crater. (China National Space Administration) The rover was put down for its nap after checking out the crater, and reawakened to make the most of the afternoon sunlight. During this time, it examined the crater using its Visible and Near-Infrared Spectrometer (VNIS), which analyses the light reflecting off surfaces to determine their chemical composition. We still don't have answers from that analysis, but the surface of the Moon is quite dry, so it's possible the stuff found by the rover is more of a hardened molten material than a squishy, jelly-like substance. Which, even if they weren't on the near side, would rule out a pile of tardigrades. Yutu-2 went back to sleep on August 7 for the duration of the lunar night, since it runs on solar power. It awoke on August 25 for the next lunar day, and has been continuing its journey west in search of new discoveries.
Scientists have found the most massive neutron star ever discovered. The star is only 15 miles across, but weighs 2.17 times more than our sun. They were only able to determine the mass of the star because it's part of a binary system with a white dwarf, somehow the white dwarf warped the space around the two stars in a way that they could measure the mass of both using something called "The Shapiro Delay". https://www.cnn.com/2019/09/16/world/massive-neutron-star-scn/index.html Had to look it up. "Radar signals passing near a massive object take slightly longer to travel to a target and longer to return than they would if the mass of the object were not present. The time delay is caused by spacetime dilation, which increases the path length. In an article entitled Fourth Test of General Relativity, astrophysicist Irwin Shapiro wrote:[1] Because, according to the general theory, the speed of a light wave depends on the strength of the gravitational potential along its path, these time delays should thereby be increased by almost 2×10−4 sec when the radar pulses pass near the sun. Such a change, equivalent to 60 km in distance, could now be measured over the required path length to within about 5 to 10% with presently obtainable equipment." Might be the next prime candidate for a black hole, it would be amazing to have eyes on it if a gamma ray burst ever occurred.
Cliffs: basically, it is hypothesized that a couple of massive asteroids collided in the asteroid belt. the resultant dust made it's way to Earth's orbit and into our atmosphere, where it cause an ice age. This ice age stressed the ocean ecosystem(s) and drove evolution that caused an explosion in Earth's biodiversity.
In other black hole news, that "9th planet" in the solar system, a new study proposes could actually be a primordial black hole instead of a planet https://arxiv.org/abs/1909.11090
Really hope we don't have to end up putting as asterisk by Saturn's moon numbers due to some performance enhancing stuff that comes out in the next couple years.
You tell me. If it was a black hole, I believe it would have to be the size of a bowling ball with a mass 10x of the Earth. Or so I read.
So my 5 year old is learning about Space and he really wants a telescope. Figured this would be a good place to ask advice on some easy to use and good telescopes that I could purchase for him?
Nuts is above 1000 and above He's young, he'll love to do it with you, he'll love to look at the sky and see bright objects millions of miles away and think look what I found, or to see our neighboring planets and let his imagination run wild of what lies beyond. If you live in a bright area, you may have to travel a bit though. https://www.meade.com/lightbridge-mini-114.html $150 - solid optics, needs a table, could use better eye pieces, reliable mount, good accessories for a beginner. Could consider upgrading to the Mini 130 at $175 for better optics and better resolution due to a bigger aperture https://www.highpointscientific.com/zhumell-z114-portable-altazimuth-reflector-telescope-zhus002-1 $150 - same specs as the 114 above but with better eyepieces and a rotating tube ring https://shop.astronomerswithoutborders.org/products/awb-onesky-reflector-telescope $200 - has the same optics as the Mini 130 and Z114 mentioned above, but brings a tress tube that can be collapsed (helps the tube eliminate air currents and allows it to be used in most weather conditions), better eyepieces, and a collimation tool (helps aligns your mirrors and optics for best focus), best aperture for the price range, collects a lot of light The Starblast is another option around $200 as well
Are you asking if we live in a city? The answer is no. If you are asking something else please explain. I don’t know much about telescopes and viewing. I just know my is so into it.
I saw one on Amazing is was like 700. You could punch in coordinates and it would adjust the telescope to view planets, stars. Seemed like a good idea because his daddy has no idea where to look lol. Thanks for the suggestions. He’s so into space. The other day he came home from school, grabbed his white board and went on to draw the sun, planets and made sure to put them in correct order and draw them according to size. Really awesome to see him into it. So I want to support that love as much as possible
That's great of you two Wish I started when I was younger, but you gotta start somewhere! Just don't get a PowerSeeker.
This was the one I found on amazon that was highly rated on a few list. Not sure if this is over the top.
The NexStar and other GoTos a great telescope for visual or very bright celestial object like the moon or planet if you want to do photography. Because this is an Alt AZ mount, it's not recommended for anything that requires long exposure (DSO). You would need an equatorial mount. My preference would be to buy an 8-10" dob in that price range https://www.highpointscientific.com/brands/apertura/apertura-ad8-8inch-dobsonian-telescope-ad8 And go from there for casual viewing
Also GoTos require alignment before each use which is not easy to get a hang of and are prone to breaking down