In 2007 China successfully destroyed one of their own aging polar-orbiting weather satellites just so they could prove they could. Debris from the destroyed satellite collided with Russia’s BLITS satellite in 2013, resulting in thousands of pieces of new space debris and is considered the most prolific and severe fragmentation in the course of five decades of space operations. Thanks China.
Now all we need is for North Korea to get their hands on that technology.
Still, space is a pretty big place and the pieces of junk are known and plotted so we can stay away from them, including little nuts and bolts travelling many times faster than a bullet.
Ever see the movie Gravity? Flaws in the science, but it was all about space junk taking out everything up there.
Yes, of course. One example rarely considered is the Oort Cloud, pictured below. The Oort cloud is thought to contain objects that occasionally become dislodged to become long-period comets. It surrounds us like a giant sphere, well beyond Neptune and any known planets.
How can you explain how we see the moon during the day to your teacher? The moon is visible in daytime because the apparent brightness (m) of reflected sunlight off the surface of the moon essentially exceeds the brightness of the blue sky, unlike the stars. That’s your simple answer.
Apparent brightness is the brightness we perceive after light passes through our atmosphere to our eyes.
Our sun and objects that reflect our sun’s rays are very bright in comparison with their surroundings. Any magnitude below -4 cannot be seen in daytime (the lower the number the brighter the object). Our sun is -26 and the full moon is -12.5, well above the magnitude necessary to see in daytime, -4. The brightest star has a magnitude of -1, dimmer than the required -4 magnitude required to be seen in daylight. All other stars are dimmer still.
If you are wanting to think outside the box you might want to look at the Chinese space plans to launch a manned mission to Mars by 2020, at least according to CNN. If true, China will be the first ones to put footprints on Mars.
Your operative word is “assume.” There are almost certainly aliens in our big universe. It’s just that they can’t visit us and we can’t visit them because of the pokey nature of the speed of light. We assume they’d do us harm because it makes for great Hollywood movies!
No technology was lost.
Going to the moon is very expensive, very far away and has no value now that the cold war with the Soviet Union is over. We can’t even balance the budget and Trump wants to cut taxes. During the Kennedy era going to the moon was a competition as to which country had the best space exploration. That’s over sorta except for Mars. Probably the first country to set foot on Mars will be China.
Going to the moon wasn’t a hoax. You can see trails left by the lunar rovers and reflect lasers off the reflector left behind just for that purpose. We can’t hide anything, even from Wikileaks, what to speak of a faked lunar mission 9 times over. The biggest hoax is the hoax theory itself.
Since President Obama the focus has been to go to Mars, but the moon is not out of the picture. NASA intends to harvest rocks from a nearby asteroid with a robotic spaceship, and then orbit that spaceship around the moon. They then plan to have a manned mission to orbit the moon, rendezvous with that robotic satellite and bring some of those asteroid rocks back to Earth for examination.
In the meantime, we have satellites orbiting and mapping the moon in detail.
No, but a great question. NASA once pointed the Hubble Space telescope at a very tiny area of space previously thought to contain nothing – a gap in the stars if you will. What they photographed is below. It’s called NASA’s deep space photo. The galaxies in the image are billions of light years away. As you can see, as with all other galaxy pictures, galaxies are scattered everywhere wherever you look, up down and in between, and tilted this way or that way.