Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature. Like magnets, they also have two poles. Although they are …
Globular clusters are a popular object to watch in telescopes. But not only our own galaxy has globular clusters, also other galaxies do. M31, one of the nearest galaxies, enables us to view globular clusters in other galaxies. This map, overlaid on one of my own images, gives an overview of a large part of …
The Pelican Nebula (also known as IC5070 and IC5067) is an H II region associated with the North America Nebula in the constellation Cygnus. The nebula resembles a pelican in shape, hence the name. The Pelican Nebula is a large area of emission nebula in the constellation Cygnus (the Swan), close to Deneb, and divided …
Gassendi is a large lunar crater feature located at the northern edge of Mare Humorum. The formation has been inundated by lava during the formation of the mare, so only the rim and the multiple central peaks remain above the surface. The outer rim is worn and eroded, although it retains a generally circular form. …
Schickard is a lunar impact crater of the form called a walled plain. It lies in the southwest sector of the Moon, near the lunar limb. As a result the crater appears oblong due to foreshortening. Attached to the northern rim is the lesser crater Lehmann, and to the northeast is the even smaller Drebbel. …
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the “Red Planet”, as the iron oxide prevalent on its surface gives it a reddish appearance. Mars is a terrestrial planet with a thin atmosphere, having surface …
Aristarchus is a prominent lunar impact crater that lies in the northwest part of the Moon’s near side. It is considered the brightest of the large formations on the lunar surface, with an albedo nearly double that of most lunar features. The feature is bright enough to be visible to the naked eye, and is …
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature. Like magnets, they also have two poles. Although they are …
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields. It has a diameter of about 1,392,000 km, about 109 times that of Earth, and its mass (about 2×10^30 kilograms, 330,000 times that of Earth) accounts for about 99.86% …
The Horsehead Nebula (also known as Barnard 33 in emission nebula IC 434) is a dark nebula in the constellation Orion. The nebula is located just to the south of the star Alnitak, which is farthest east on Orion’s Belt, and is part of the much larger Orion Molecular Cloud Complex. The Horsehead Nebula is …