What is "janssen"

Janssen is an ancient impact crater located in the highland region near the southeastern lunar limb. The entire structure has been heavily worn and is marked by many lesser crater impacts. The outer wall is breached in multiple locations, but the outline of the crater rim can still be observed. The wall forms a distinctive hexagonal shape upon the rugged lunar surface, with a slight curvature at the vertices.

The prominent crater Fabricius lies entirely within the outer wall, in the northeast quadrant of the floor. A number of other lesser, but still notable craters mark the crater floor. Connected to the northeast rim is Metius, and to the north is the heavily worn Brenner. Southeast of Janssen are the co-joined craters Steinheil and Watt. Astride the southwest wall is the smaller Lockyer. Further to the east, although appearing nearby due to elongation, is the huge Vallis Rheita.

In the southern two-thirds of Janssen can be discerned the remains of a large, concentric crater, the wall of which is overlaid by Fabricus. The floor of this inner depression contains a rille system named the Rimae Janssen. The rille curves from the rim of Fabricius to the southeast of the outer wall of Janssen, extending for a distance of up to 140 kilometers.

Janssen may refer to:

People with the surname Janssen:

• Janssen (surname)

Other:

• Janssen (lunar crater)
• Janssen (Martian crater)
• Janssen (planet) or 55 Cancri e, an exoplanet
• Janssen Biotech, American biotechnology company
• Janssen Pharmaceutica, a Belgian company
• Janssen-Cilag, company formed by merger of Janssen Pharmaceutica and Cilag
• E. Janssen Building, a historic building in Eureka, California

Janssen is a surname. Notable people with the surname include:

• Saint Arnold Janssen (1837–1909), German founder of the Society of the Divine Word
• Benno Janssen (1874–1964), American architect
• Benny Janssen Dutch sidecarcross rider
• Brian Janssen (born 1962), Australian boxer of the 1980s
• Casey Janssen (born 1981), American baseball player for the Washington Nationals
• Constant Janssen (1895–1970), Belgian founder of predecessor of Janssen Pharmaceutica
• David Janssen (1931–1980), American film and television actor
• Famke Janssen (born 1965), Dutch actress
• Horst Janssen (1929–1995), German printmaker
• Jan Janssen (born 1940), Dutch professional cyclist
• Johannes Janssen (1829–1891), German historian
• Marco A. Janssen (born 1969), Dutch econometrist
• Paul Janssen (1926–2003), Belgian founder of Janssen Pharmaceutica
• Pierre Jules César Janssen (1824–1907), French astronomer
• René Janssen (born 1959), Dutch nanotechnologist
• Rik Janssen (born 1957), Dutch politician
• Ronald Janssen (born 1971), Belgian serial killer
• Ruud Janssen (born 1959), Dutch Fluxus and mail artist
• Tiny Janssen Dutch sidecarcross rider
• Vincent Janssen (born 1994), Dutch professional footballer
• Zacharias Janssen (1580–1638), Dutch spectacle-maker; invented a compound microscope

Janssen Crater is an impact crater in the Arabia quadrangle on Mars at 2.7° N and 322.5° W. and is 158.0 km in diameter. Its name was approved in 1973, and it was named after Pierre Janssen. Some close up images of the crater reveal layers in a floor deposit. A picture below show these layers, as well as dark slope streaks. The darker the streak, the younger it is. The layers on the floor of Janssen may have been formed on the bottom of lakes.