Lifeboat Foundation

An image from the Hubble Space Telescope shared this week by NASA shows an unusual interaction of four dwarf galaxies. There are two small galaxies which are so close together that they look like one object, called NGC 1,741, located at the top of the image. Then there is another cigar-shaped galaxy close by to the right, and a fourth galaxy in the bottom left which is connected to the other three by a stream of young stars.

Together, the four galaxies make up a set called the Hickson Compact Group 31, or HCG 31. The group is located 166 million light-years away from Earth, which is relatively close for seeing interacting dwarf galaxies. The galaxies are currently so close together, at within 75,000 light-years of each other, that all four of them would fit within the Milky Way.

The early Solar System was a much different place than that seen today.

The Solar System may have started with five gas giants, but according to the Nice model, Planet X may have been flung into interstellar space.

There’s a mysterious X-ray source and other unknowns in this Hubble telescope photo of the Needle’s Eye galaxy.

A hand-held laser pointer produces no noticeable recoil forces when it is “fired” — even though it emits a directed stream of light particles. The reason for this is simply because of its relatively enormous mass compared to the very tiny recoil impulses that the light particles cause when they leave the laser pointer.

However, it has long been clear that optical recoil forces can indeed have a significant effect on correspondingly small particles. For example, the tails of comets point away from the Sun partly due to light pressure. The propulsion of light spacecraft via light sails has also been discussed repeatedly, most recently in connection with the “starshot” project, in which a fleet of miniature spacecraft is to be sent to Alpha Centauri.

Should we send robots on space missions instead of humans?

The cost differences are huge. In fact, NASA could pursue dozens of robotic missions for the cost of a single human mission. Also worth considering–wealthy entrepreneurs have made great advances recently with private space efforts.

Given the large ambitions for private human space flight, isn’t it time to phase out NASA’s human missions? The private sector has gained ground, and so the government should yield.

Continue reading “Should we send robots on space missions” »

Woah.

Voyager launched in 1977, and now humankind’s most distant object is transmitting data that doesn’t make sense.