On November 28, 1964, the Mariner 4 spacecraft was launched. It continued on toward Mars and was the first probe to return close range images of that planet. As a result of this successful mission, November 28 is known as Red Planet Day. So let’s take a few minutes to learn a bit about Mars.
The planet Mars has been known since antiquity, and its rusty color gave our ancestors the idea that it was associated with blood and, by extension, the god of war.
In more modern times, the telescope was used to try to study Mars. One notable scientist was Giovanni Schiaparelli. Because Mars, even when at its closest to Earth, appears much smaller than the Moon (about 1.3% the apparent size of the Moon), it is difficult to see detail on Mars from Earth. When humans look at something near its resolution limit, the brain tends to “fill in the gaps” and create optical illusions of lines and features that aren’t really there. Schiaparelli used the word “canali” to describe some of the lines he thought he saw. The word “canali” means “channel,” and due to a mistranslation, was translated as “canals.” Suddenly Mars had canals and the speculation about life on Mars began. Intelligent lifeforms were struggling to survive on the dry desert world and must have built canals to funnel water from the polar caps to survive. More »
Comets are a fascinating area of astronomy that holds a special place in the hearts of the public, not just astronomers. This fact mainly holds due to the potential for a new comet to become visible to the naked eye, a rather uncommon event. Maybe the same mechanism that keeps this fascination going in the public is the same one that makes gamblers keep going back to the poker table. Usually, you will lose at gambling, but every now and then you might win big. In a way, the same holds for comets. More »
Imagine you want to send a one-ton package to Mars, land it safely on the surface, and have it move around after it lands. First, the package has to survive atmospheric entry on Mars, which heats the package to 1,600 degrees. After this, the package has to deploy a supersonic parachute capable of withstanding 9 gs of force to slow down. More »
In astronomy, one of the most prized pieces of data is to determine the distance to an astronomical body. Prior to the sixteenth century, the distance between planets and the Sun was an educated guess, but an accurate value had not been determined. Without the ability to pace off the distance or use a physical measuring stick, there was no direct way to determine this. How far was the Earth from the Sun? The distance between the Earth and Sun, known as an astronomical unit, was a key piece of missing data. In 1761, one of the first international scientific endeavors was carried out. Ships carrying scientists from numerous countries were dispatched to various observation locations to observe a relatively rare event. The planet Venus was going to pass between the Earth and the Sun, and, from our point of view, would move across the solar disk.
I was a child of the late 70s and early 80s, so I was witness to the early evolution of home computers and the trends that came along with them. It’s amazing when you see the large-screen displays of today and compare them to the giant bulky monitors from those early days. It’s also amazing to see how the capabilities of these displays have improved with time, something we often take for granted. We are spoiled with giant widescreen monitors that sometimes exceed 2500x1400 pixels in size. I remember taking my first steps in computer science in school using graphics on an Apple IIe that supported 280x192 pixels! (We also walked to school uphill both ways in the snow with no shoes, because those were a luxury.) I’m sure there are those of you in the audience who remember even earlier days with even more primitive capabilities (TRS 80?).
Today there are a high number of devices that support all manner of display resolutions. Many applications that deal with graphics will often present you with dialog boxes when you save your images that give you things like a pixels per inch (PPI) setting as well as the memory used by the image. Often these little things are taken for granted, but they can be useful for planning how to use your results. Wolfram|Alpha has now added some extensions to its functionality that provide some basic tools to help in this area.