Cosmic Distance Scales - The Solar System About the Image One way to help visualize the relative distances in the solar system is to imagine a model in which the solar system is reduced in size by a factor of a billion (109). The Earth is then about 1.3 cm in diameter (the size of a grape). The Moon orbits about a foot away. The Sun is 1.5 meters in diameter (about the height of a man) and 150 meters (about a city block) from the Earth. Distance Information Distances in the solar system are commonly measured in Astronomical Units (AU). The Moon, the closest solar system body to us, is about 400,000 km away from the Earth, which means it takes about 2 seconds for radio signal from Earth to reach the Moon and travel back. The most distant planet from the Earth isn't Pluto anymore. Pluto is still an interesting member of the solar system, however - its orbit is actually very eccentric and takes Pluto 4,400,000,000 - 7,400,000,000 km (30 - 49 AU) from the Sun. The Outer Reaches of the Solar System Parallax Radar Travel Time
Visual Satellite Observer's Home Page From left to right the above images are: A Soyuz manned capsule. Satellite captured on a long exposure photograph. The external tank caught just after separation during the STS-2 shuttle mission. If you have ever star-gazed shortly after sunset or before sunrise, you have probably noticed one or two "stars" sailing gracefully across the sky. These are Earth-orbiting satellites, visible due to the reflection of the Sun's light off their surfaces toward the observer. Hundreds of satellites are visible to the unaided eye; thousands are visible using binoculars and telescopes. Amateur astronomers seeking new challenges, find that spotting faint, rapidly moving satellites, such as the tiny Vanguard 1 (America's second satellite), are comparable to spotting a distant galaxy. Positional observers precisely measure the time and position of satellites as they cross the sky. This web site provides information on all facets of visual satellite observation:
Explore Space Science Activities Overview Jump Start: Jupiter! is a 60-minute kick-off for children ages 8 to 13 that sets the stage for further explorations and activities in Explore! Jupiter's Family Secrets. As a group, children discuss what they know about the solar system and Jupiter. What's the Point? The solar system is a family of eight planets (four giant planets and four inner, rocky planets), an asteroid belt, several dwarf planets, and numerous small bodies such as comets in orbit around the Sun. Materials For each group of 20 to 30 children: For each child: For the facilitator: Preparation Review the complete background information. Activity 1. How many stars are in our solar system? 2. 3. What is its surface like? 4. 5. 6. How are the four giant planets alike? Invite the children to summarize their findings in their journals. 7. Conclusion Ask the children if they would also like to learn more about Jupiter and our solar system's family history.
Albedo Geolocation in the Browser « Mozilla Webdev Firefox 3.5 makes it super simple to discover the location of a user on your website You can read more about it from Doug Turner or the official Mozilla page, but today I want to look at how to use the new API. The following image is a screenshot of geolocation plus Google maps. If you’re running Firefox 3.5, we’ll replace that with a real map showing your current position. Geolocation finding me at the Mozilla office. First, we should check that the browser supports the Geolocation API: if (! Now that we’ve cleared out the riff-raff we can dive in to the new feature: navigator.geolocation.getCurrentPosition() I love the simplicity of this API; that’s all you need to know to get the user’s position! navigator.geolocation.getCurrentPosition(function(position) { alert(position.coords.latitude + ", " + position.coords.longitude); }); Since it takes a few seconds to gather location data and send it up to the geolocation services, we must use an asynchronous callback instead of a return value.
Black Holes: Gravity's Relentless Pull Black holes are places where ordinary gravity has become so extreme that it overwhelms all other forces in the Universe. Once inside, nothing can escape a black hole's gravity — not even light. Yet we know that black holes exist. We know how they are born, where they occur, and why they exist in different sizes. We even know what would happen if you fell into one. The nearest black hole is many lightyears away, so we don't have to worry about threats to the Earth. For a fully interactive multimedia experience, click Journey to a Black Hole (fast internet connection recommended). 2005 Pirelli Award: Winner Top Prize & Physics Category note Mars Science Laboratory Fun Send a Postcard to Curiosity - 08/06/2013 Mars on the Go! Curiosity's Mission Enjoy this slideshow about Curiosity's mission: To see if Mars ever had the right conditions to support life! Learn About The Rover Curiosity's parts are similar to what a human would need to explore Mars (body, brains, eyes, arm, legs, etc.). Landing On Mars Curiosity Latest Mission Updates Curiosity's Location See a map of Curiosity's current location and check out the mission clock, which tells you how many days Curiosity has been on Mars.More >> Latest Raw Images - 07/16/2014 Follow Curiosity's Journey Follow Curiosity's journey, get the latest traverse info and daily weather data. Curiosity Scientific Data NASA's Planetary Data System archives and distributes scientific data from NASA planetary missions, astronomical observations, and laboratory measurements, including Curiosity!