Related papers: Mars Before the Space Age
For several decades a portrait of Johannes Kepler has been widely circulating among professional astronomers, scientific and academic institutions, and the general public. Despite its provenance and identification having been questioned in…
Star forming galaxies represent a valuable tracer of cosmic history. Recent observational progress with Hubble Space Telescope has led to the discovery and study of the earliest-known galaxies corresponding to a period when the Universe was…
The Era of the First Stars is one of the last unknown frontiers for exploration: a poorly understood billion years missing from our cosmological timeline. We have now developed several methods for finally filling in the lost billion years…
Coronal mass ejections (CMEs) were discovered in the early 1970s when space-borne coronagraphs revealed that eruptions of plasma are ejected from the Sun. Today, it is known that the Sun produces eruptive flares, filament eruptions, coronal…
Coronal astronomy is by now a fairly mature discipline, with a quarter century having gone by since the detection of the first stellar X-ray coronal source (Capella), and having benefitted from a series of major orbiting observing…
The current knowledge of Mercury orbit has mainly been gained by direct radar ranging obtained from the 60s to 1998 and by five Mercury flybys made by Mariner 10 in the 70s, and MESSENGER made in 2008 and 2009. On March 18, 2011, MESSENGER…
Earth has had oceans for nearly four billion years and Mars had lakes and rivers 3.5-3.8 billion years ago. However, it is still unknown whether water has ever condensed on the surface of Venus because the planet - now completely dry - has…
Galileo Galilei believed that stars were distant suns whose sizes, measured via his telescope, were a direct indication of distance -- fainter stars (appearing smaller in the telescope) were farther away than brighter ones. Galileo argued…
For more than 3.5 billion years, life experienced dramatic environmental extremes on Earth. These include shifts from oxygen-less to over-oxygenated atmospheres and cycling between hothouse conditions and global glaciations. Meanwhile, an…
Three major planets, Venus, Earth, and Mercury formed out of the solar nebula. A fourth planetesimal, Theia, also formed near Earth where it collided in a giant impact, rebounding as the planet Mars. During this impact Earth lost…
For over a decade, scientists at NASA's Jet Propulsion Laboratory (JPL) have been recording measurements from the Martian surface as a part of the Mars Exploration Rovers mission. One quantity of interest has been the opacity of Mars's…
Exploration is one of the attentive endeavor to mankind and a strategy for evolution. We have been incessantly reconnoitering our planet and universe from Mesopotamian era to modern era. The progression of rocketry and planetary science in…
In 1492, for the first time, an unknown ocean opened up before sailors: weeks of navigation and no idea how to pinpoint their location. Since ancient times, navigators had known how to determine latitude by using the North Star, but the…
Some 400 years after Galileo, modern telescopes have enabled humanity to "see" what the natural eye cannot. Astronomical images today contain information about incredibly large objects located across vast distances and reveal information…
Two decades ago, astronomers began detecting planets orbiting stars other than our Sun, so-called exoplanets. Since that time, the rate of detections and the sensitivity to ever-smaller planets has improved dramatically with several…
The InSight mission, featuring continuous high-frequency high-sensitivity pressure measurements, is in ideal position to study the active atmospheric turbulence of Mars. Data acquired during 1.25 Martian year allows us to study the seasonal…
Exoplanetary science has reached a historic moment. The James Webb Space Telescope will be capable of probing the atmospheres of rocky planets, and perhaps even search for biologically produced gases. However this is contingent on…
There are many reasons why it is important to increase the number of known pulsars. Not only do pulsar searches continue to improve statistical estimates of, for example, pulsar birthrates, lifetimes and the Galactic distribution, but they…
Surrounded by stunning Algarve landscapes not far from where Henry the Navigator organized the voyages that mapped the Earth, particle astrophysicists discussed new initiatives to explore the cosmos. While first generation experiments…
Although the extragalactic nature of quasars was discussed as early as 1960, it was rejected largely because of preconceived ideas about what appeared to be an unrealistically high radio and optical luminosity. Following the 1962…