Falcon 9 is a two-stage-to-orbit medium lift launch vehicle designed and manufactured by SpaceX in the United States. It is powered by Merlin engines, also developed by SpaceX, burning liquid oxygen (LOX) and rocket-grade kerosene (RP-1) propellants. Its name is derived from the Millennium Falcon and the nine engines of the rocket’s first stage. The rocket evolved with versions v1. 0 (2010–2013), v1. 1 (2013–2016), v1. 2 “Full Thrust” (2015–2018), and its Block 5 variant, flying since May 2018. Unlike most rockets, which are expendable launch systems, Falcon 9 is partially reusable, with the first stage capable of re-entering the atmosphere and landing back vertically after separating from the second stage. This feat was achieved for the first time on flight 20 with the v1. 2 version in December 2015.
It's hard not to like Sagittarians, for their openness, generosity, and sociable nature. They are deep thinkers in search of universal wisdom, attracting them to philosophy and religion. Their minds can grasp both the details and the bigger picture: they can think with intellectual precision but also intuitively. That unusual combination of thinking skills allows them to be at the forefront of creative ideas. They are idealistic and care about the state of the world, leading them to take up vocations in medicine, education, religion, and politics. They need to be highly independent in their work and in their personal lives. There are over 100 moons dancing around the eight major planets of our Sun's family. Most of them are small, frozen, icy objects, harboring only a relatively scanty amount of rocky material, that circle around the quartet of giant gaseous planets that dwell in the outer, frigid realm of our Solar System--far from the comforting warmth and brilliance of our Star. The quartet of majestic, giant denizens of our outer Solar System--Jupiter, Saturn, Uranus, and Neptune--are enveloped with gaseous atmospheres, and orbited by a multitude of dancing, sparkling moons and moonlets. In marked contrast, the inner region of our Solar System--where our Earth dwells--is almost bereft of moons. Of the quartet of relatively petite, rocky "terrestrial" planets--Mercury, Venus, Earth, and Mars--only Earth is circled by a large Moon. Mercury and Venus are moonless, and Mars is orbited by a duo of tiny, lumpy, potato-shaped moons, Phobos and Deimos. Phobos and Deimos are probably escaped asteroids, born in the Main Asteroid Belt between Mars and Jupiter, that were captured by the gravitational embrace of the Red Planet long ago. The discovery of a moon for Makemake may have solved one perplexing puzzle concerning this distant, icy object. Earlier infrared studies of the dwarf planet showed that while Makemake's surface is almost entirely frozen and bright, some areas seem to be warmer than other areas. Astronomers had suggested that this discrepancy may be the result of our Sun warming certain dark patches on Makemake's surface. However, unless Makemake is in a special orientation, these mysterious dark patches should cause the ice dwarf's brightness to vary substantially as it rotates. But this amount of variability has not been observed.