Los cielos de Marte llevan la contraria a los de la Tierra: allí veríamos atardeceres azules y días rojos xataka.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from xataka.com Daily Mail and Mail on Sunday newspapers.
By Patrick Dennis (not verified) on 27 Jan 2015 #permalink
@Patrick Dennis #1: Parallax? I guess you mean effective parallax for observers on opposite sides of the Earth; clearly single-observer parallax is infinitesimal. At opposition, Jupiter is a minimum of 4 AU (6e+8 km) from Earth, which is where any parallax would be maximized. Using a baseline of 12,800 km, the parallax is 0.213 mrad or 0.73 arcminutes. At opposition, Jupiter s angular diameter is 50 arcseconds, or 0.83 arcminutes, comparable to the parallax.
What is more significant is the speed of light! The difference in distance to Jupiter between opposition (4 AU) and conjunction (12 AU) is 1.2e+9 km. That corresponds to a light travel-time of about 4000 seconds, or more than an hour! If you used ephmerides derived at opposition, you could (near conjunction) be off by an hour in your calculation of time, or as much as 1000 km in distance!
October 29, 2017
What better way to say farewell than with a slew of costume pictures from this year s (coming) Halloween? Happy Halloween 2017! From Ethan Siegel and Starts With A Bang. Keep looking to the Universe. And we ll have a lifetime of wonderful things to still explore.
Goodbye, Scienceblogs,…
October 28, 2017 Delay is the deadliest form of denial. -C. Northcote Parkinson
Every massless particle and wave travels at the speed of light when it moves through a vacuum. Over a distance of 130 million light years, the gamma rays and gravitational waves emitted by merging neutron stars arrived offset by a…
October 27, 2017
“On what can we now place our hopes of solving the many riddles which still exist as to the origin and composition of cosmic rays?” –Victor Francis Hess
January 12, 2021
New work agrees with older research suggesting the oldest light in the universe – from the most distant galaxy yet known – started its journey toward us 13.77 billion years ago.
View larger. | In 2013, the Planck space telescope released the most detailed map to date of the cosmic microwave background, the relic radiation from the Big Bang. It was the mission’s first all-sky picture of the oldest light in our universe, imprinted on the sky when it was just 380,000 years old. Now a new, independent study agrees with Planck’s results. That’s good news for astronomers trying to pin down the universe’s age and rate of expansion. Image via ESA.
Experiment Changes Understanding Of Black Holes popularmechanics.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from popularmechanics.com Daily Mail and Mail on Sunday newspapers.