We recently posted a blog entry celebrating the anniversary of the Apollo 11 landing on the Moon. Now, just a couple weeks later, we are preparing for another first: the European Space Agency’s attempt to orbit and then land on a comet. The Rosetta spacecraft was launched in 2004 with the ultimate goal of orbiting and landing on comet 67P/Churyumov–Gerasimenko. Since the launch, Rosetta has already flown by asteroid Steins, in 2008, and asteroid 21 Lutetia, in 2010.
NASA and the European Space Agency (ESA) have a long history of sending probes to other solar system bodies that then orbit those bodies. The bodies have usually been nice, well-behaved, and spherical, making orbital calculations a fairly standard thing. But, as Rosetta recently started to approach comet 67P, we began to get our first views of this alien world. And it is far from spherical. More »
Although I was born several years after the first Apollo Moon landing, the excitement surrounding the Apollo Moon landings and the space exploration enthusiasm it fostered drastically affected my childhood and shaped the direction my later life would follow. The space race, arguably peaking with the Apollo Moon landings, generated a funding explosion for science education that allowed many planetariums to be built and a phase of education encouragement that affected many of my generation. If we could land on the Moon, imagine what else we might achieve if we worked hard enough.
On July 20, we celebrate the 45th anniversary of the Apollo 11 Moon landing. This landing began a sequence of Moon landings that ended with Apollo 17. We can leverage Wolfram|Alpha and the recently released Mathematica 10 to help us celebrate and continue exploring (data, in this case). The available data includes dates, crew information, and landing coordinates.
Let’s explore the crew information first. As with many famous people, Wolfram|Alpha gives a fair amount of information like birth dates and locations, pictures, time lines, height information, and familial information. More »
Last week the weather here was pretty bizarre. Overnight, it went from 66°F and outdoor soccer matches to 28°F and a blanket of snow and ice. You know what else is pretty bizarre? Some of the things people can—and do—ask Wolfram|Alpha. So in case, like us, you’re stuck inside for a few more weeks of winter and in need of inspiration, read on for a few examples of some of the more… unique types of queries that you, too, can ask Wolfram|Alpha. More »
“At breakfast time I was sitting by the house at Vanavara Trading Post, facing north…. I suddenly saw that directly to the north, over Onkoul’s Tunguska Road, the sky split in two and fire appeared high and wide over the forest. The split in the sky grew larger, and the entire northern side was covered with fire. At that moment I became so hot that I couldn’t bear it, as if my shirt was on fire; from the northern side, where the fire was, came strong heat. More »
My family lives all over, with varying worldviews and equally varied career choices, from video game producers to truck drivers. So certainly reconnecting with family, both nuclear and extended, can be a daunting holiday experience. But don’t fret—Wolfram|Alpha is here to sort you out with the perfect ice breakers.
Suppose your brother is a truck driver who plans to move to Salt Lake City, Utah, from Raleigh, North Carolina, citing dissatisfaction with his wages and the cost of fuel, and how they juxtapose to the cost of living in Raleigh. You could first show how many truck drivers are in North Carolina and Utah, and from there ask the question “What is the average wage for truck drivers in North Carolina and Utah?”
We can see that truck drivers do earn more money in Utah than in North Carolina, and the price of diesel is, at the time of this writing, pretty much the same—only a few cents difference. But moving to another part of the country is a huge decision, and even if one can earn a few thousand dollars more, is it worth it? We could compare the cost of utilities in Salt Lake City and Raleigh or, more generally, the cost of living in Salt Lake City and Raleigh. More »
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 »
Today is the summer solstice—when the Sun is at its more northern point—which marks the first day of summer, as well as the longest day in 2012. It’s a great day to go outside and take advantage of all the extra sunlight, and also a good time to take a look at all of the computations Wolfram|Alpha can do revolving around the Sun.
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.
Solar eclipses have been recorded since ancient times, often misunderstood by early observers as a dragon eating the Sun or some omen of things to come. Although we have learned the true nature of eclipses in modern times, they never cease to amaze astronomers and the public alike. You can visualize solar and lunar eclipses using a Wolfram Demonstration.
Solar eclipses happen when the Moon moves between the Earth and the Sun. The Moon blocks the Sun’s light, which puts a kink into our daily expectations, making it get dark during the day. A fuzzy estimate puts the frequency of total solar eclipses at about one or two per year. This number can vary quite a bit. Often, these eclipses are only visible along narrow paths that are in out-of-the-way places that make it difficult for them to be observed (e.g. over the open ocean). Cruise ships are often booked for the sole purpose of chasing these solar eclipses for those people willing to set sail and pay the money to do so.
On May 20 of this year, people in the western United States and Pacific Ocean islands will be in a position to observe one of these solar eclipses without having to travel on the high seas.
At about 6pm CST on March 6, there was a very powerful X 5.4 solar flare. This triggered a coronal mass ejection (CME). Indications were that the CME wasn’t squarely directed at Earth, but that a strong glancing blow to the Earth’s magnetosphere was possible. Here’s the data in Wolfram|Alpha for the flare:
There are two X-class flares during this time range. The effects of the first flare hit the Earth on March 7 and was a minor glancing blow, but caused a geomagnetic storm with effects visible in northern latitudes. More »
The next time you go stargazing, bring the power of computation along with the Wolfram Planets Reference App and Wolfram Stars Reference App for iOS. Both apps provide access to real-time data and the computational power of Wolfram|Alpha in order to perform advanced calculations and provide data on the planets and stars.
On a moonlit stroll, a young man points to the cloudless sky and says, “Look—a full moon!”
His date is not impressed. “Technically,” she replies, “the Moon’s not full until 2pm, when its ecliptic longitude is opposite to that of the Sun.”
Hoping to save his pride, he replies, “But the Moon looks completely illuminated.”
“It’s never one hundred percent illuminated,” his date says, unfazed. She’s a tough cookie. “Oh, and on this side of the world it’ll be a corn moon.”
Pretending to check his watch, the young man gets confused. He remembers his science teacher explaining that the Moon reflects sunlight and that it is full when it is on the other side of the Earth from the sun, but the nighttime half of the Earth is on the opposite side of the Sun, so how could that be 2pm? Did the newspaper say it would be a full moon tonight, or did it say tomorrow night? And what’s a corn moon?
There’s only one thing he can do: look it up on Wolfram|Alpha!
One of the latest features added to Wolfram|Alpha is more coverage of full moons and other Moon phases. Back when people got their information from only a local newspaper, it was relatively simple to say that one night or another would be a full moon, because for a specific location, the time of a full moon would be closest to midnight on that day. But now it is easy to get your information from a newspaper that is far away, so its date can be off by a day. Of course, Wolfram|Alpha detects your location, so it is able to predict the date of the next full moon in your area, and the “Precise time” button reveals the exact time the full moon will take place.
Remember that because of time zone differences, there is always part of the world that is on a different day. And that affects labels like “corn moon”, which is the first full moon in September. The beginning and ending dates of September depend on the time zone, and sometimes the full moon is close to this boundary. The next ambiguous corn moon will be in 2012. More »
Early on June 7, 2011, the Sun once again showed signs of waking up from the last solar minimum: it unleashed a powerful solar flare. The x-ray emission from this flare can be seen in Wolfram|Alpha:
Today we are releasing Wolfram Multivariable Calculus and Wolfram Astronomy, the next two apps on a growing list of Wolfram Course Assistant Apps. These course assistants will help students learn their course material using the power of Wolfram|Alpha.
The Wolfram Astronomy Course Assistant allows you to easily look up information on constellations and planets, but it can also calculate anything from the next lunar eclipse to the solar interior.
One of the most common queries on Wolfram|Alpha is a user entering his or her date of birth to see how many years, months, and days old he or she is today.
Since this feature first became popular, we added more birthday-specific features for this query type. By adding “birthday” to your query, you’ll get even more detailed information, such as a birthday countdown, a notable dates pod, and astrological birth information.
For example, submit a query such as “birthday March 29, 1990” to see how many days there are until your next birthday (time to start planning, March 29ers!) and how long it’s been since your last birthday.
Every day the Sun crosses the sky, rising in the east and setting in the west, but in detail its path is different every time. If it is winter, or if you live in the north, the Sun is lower and stays closer to the southern horizon. While the time of year and the location have similar effects, they act independently on the overall path. The Sun’s path is unique for your place and time.
You can see the sunpath today at your location; the default is the perspective of looking toward the southern horizon.
The autumnal equinox is tonight (in North America), but in Pyramid Point (a place close to the equator in the Pacific), the equinox will occur Thursday, close to noon, when the Sun will be almost overhead. More »
As you go about your day, especially during the hot summer season, you probably don’t think much about the Sun other than that it makes you want to go for a quick dip in the swimming pool to cool off. After all, the Sun rises and sets every day (for those of us outside the Arctic and Antarctic Circles), and people just take it for granted without much thought.
The Sun is far more dynamic than you might think, although thankfully we don’t usually feel direct effects of its activity from Earth’s surface. The atmosphere and magnetic field of the Earth provide a nice buffer zone that protects us.
Every 11 years, the Sun completes a cycle that is fairly regular. During solar maximum, the number of sunspots is higher than usual, and during solar minimum (which we are just coming out of), it is relatively spot free.
The Sun is still coming out of solar minimum, but activity is slowly returning. At about 8:55 UTC on August 1, a measurable solar flare triggered an event known as a coronal mass ejection (CME). This is where the “atmosphere” of the Sun sends out a burst of energized plasma. In this case, nearly the entire Earth-facing side of the Sun was involved, so effects on the Earth are more likely. Here’s the X-ray signature of the solar flare that triggered the CME:
Wolfram|Alpha’s coverage of the universe continues to grow. We have now added a large collection of observed supernovae in the universe to our ever-expanding compendium of astronomical knowledge.
What exactly is a supernova? It’s a catastrophic event in the life of a star.
The full details are very complex, but basically supernovae are the visible signs of the deaths of stars more massive than the Sun. As with all other stars, massive stars spend most of their lives fusing hydrogen gas into helium in their cores. This results in a buildup of “ash” (end product of fusion reactions) in the core that eventually chokes off the hydrogen fuel from the hottest area of the core. With no new fuel, there is less energy being produced to counter the gravity trying to squeeze the star’s huge mass more tightly together. The result is that the star’s core begins to collapse as gravity overtakes the outward pressure. This results in heating the core—eventually enough that the ash can begin fusing into heavier molecules, initially carbon and oxygen. The cycle repeats, each time beginning and ending with different products and creating the next fuel source. Eventually, the core contains iron. Iron cannot liberate energy from fusion, so at this point, energy generation in the core suddenly stops, and the full mass of the star comes crashing down and a shock wave rips the star apart. This explosion is called a Type II supernova and results in the formation of a neutron star (or more rarely a black hole). More »
Sitting in your office watching and cursing the rainy outdoors, have you ever wondered what the weather beyond our protective atmosphere is like?
Yes, there is weather even in the empty space above Earth’s atmosphere. Space weather typically refers to phenomena resulting from solar activity. It’s also one of the latest content additions to Wolfram|Alpha. Space weather includes things like sunspots, solar X-rays, and solar wind, as well as their effects on the Earth itself (e.g. aurorae, radio communication blackouts, and in extreme cases power outages).
The Sun has an 11-year cycle. Every 11 years, the number of sunspots rises to a peak and then falls to a minimum. Sunspots result from areas of strong magnetic fields on the Sun that cool the surrounding gas and makes the gas appear darker. When these tangled magnetic fields reconnect, the plasma carried along with it can be flung with huge amounts of energy away from the Sun. If it is directed toward Earth, we may observe a number of effects. Depending on how the magnetic field is oriented, it may bounce off the Earth’s magnetic field with no effect. If oriented the other way, the plasma funnels down the Earth’s magnetic field lines until it encounters the atmosphere, causing it to glow. This glowing is known as the aurora borealis in the northern hemisphere and the aurora australis in the southern hemisphere.
The sunspot cycle likely plays a role in Earth’s global climate. The exact nature of its effect is still a hot area of active research. More sunspots mean more energy is likely to be absorbed by the Earth from the Sun. Fewer sunspots mean less energy and potentially a cooler climate. Between 1645 and 1715, sunspots on the Sun nearly vanished. During the same period, called the Maunder minimum, Europe experienced colder-than-average temperatures, contributing to what some have called “the little ice age”. Data for sunspots goes back much further than most other space weather data. Most other phenomena could not be measured until the advent of artificial satellites, and many much more recently than that.
In 1859, the first and most powerful solar flare ever observed occurred, known as the Carrington event. Within a couple of days of the flare, the Earth’s magnetic field oscillated wildly from the magnetized plasma thrown toward us. The magnetic field lines of the Earth bounced back and forth across telegraph wires, causing massive failures and even melted wires from the induced currents. An event of that strength today would cause untold havoc, as we are far more dependent on telecommunications via both satellites and land-based wires. More »
Have you ever wondered why you often see this example of the International Space Station (ISS) in promotion pieces for Wolfram|Alpha and the Wolfram|Alpha App? Aside from the example being visually interesting, the results highlight Wolfram|Alpha’s ability to make complex real-time computations.
Wolfram|Alpha provides some great real-time computations in many, many areas, including satellites. So what is a satellite? There are many definitions, but here we use the term to describe any artificial object in orbit around Earth that has an official North American Aerospace Defense Command (NORAD) number. This means NORAD tracks it and has assigned an official catalog number to it. The code behind Wolfram|Alpha’s dynamic satellite computations is rather complex. More »
Four hundred years ago, on January 7, 1610, Galileo pointed his telescope at the planet Jupiter and discovered that it had its own moons. This discovery changed our perspective on the universe.
Prior to Galileo’s discovery, the Earth-centric Ptolemaic system was the standard view of the cosmos where Earth was the center–heaven was above and Earth was below. Copernicus had proposed a heliocentric model, but it was a mental exercise meant to simplify the complicated Ptolemaic system. Galileo’s discovery was the first one that showed evidence that something was orbiting a body other than Earth. If Jupiter had things in orbit around it, why couldn’t other bodies?
At the time telescopes were cutting-edge, and only a few people had them. What Galileo did was an instructive example on how to combine technology and curiosity.
Among the pods about Jupiter, there is a graphic showing the current configuration of the so-called “Galilean moons”, the ones Galileo saw 400 years ago: Io, Europa, Ganymede, and Callisto.
You can even virtually recreate Galileo’s observations for yourself. Here’s how he depicted what he saw 400 years ago on the night of January 7:
And here is what he saw a few days later:
In Galileo’s diagrams, the circle represents Jupiter, and the asterisks represent the moons he observed. He didn’t know they were moons until the second observation, when they had changed position. More »
When astronomers observe a distant object in the universe, how do they know how far away it is? One method involves the object’s redshift.
What is redshift? It is a shift in the wavelength of electromagnetic radiation toward the longer-wavelength (red) end of the spectrum. Astronomers measure redshift by looking at the spectrum of light from a given distant object.
The assumption pod at the top indicates that Wolfram|Alpha has interpreted our “redshift” query as “cosmological redshift”. The “more” menu there lets you access alternate interpretations. More »
Whether you are an astronomy student, an educator, or a hobbyist with an eye to the sky, Wolfram|Alpha is a great resource for exploring astronomy data. A while back we posted an introduction to using Wolfram|Alpha to compute and explore properties and locations for objects and events in our solar system. Since then we’ve added a new set of data we’d like to share: solar system features.
Ever wanted to explore the solar system? If so, you might like to take a look at a new set of data available on Wolfram|Alpha: the complete catalog of over 14,000 officially recognized and named solar system features maintained by the United States Geological Survey (USGS). Each feature includes not only its name, but also what type of feature it is, what astronomical body it’s on, and its surface coordinates. For most named features, Wolfram|Alpha also includes a surface map showing where it is located on its parent body. Let’s go exploring!
The amount of activity that takes place here on planet Earth is at times unfathomable. But it’s the merest drop in the bucket in comparison to the boundless amounts of activity in our universe—Earth is merely one planet within the Milky Way Galaxy. Most deep-sky objects cannot be seen by the naked eye, but observers looking through a telescope are treated to views of colorful clusters of light and fuzzy clouds of gas in the sky. Here we’ll demonstrate ways Wolfram|Alpha can help you find deep-sky objects such as galaxies, nebulae, and star clusters—our universe has about 100 billion member galaxies, and with so many, it’s nice to have a place to start.
Querying “galaxies” in Wolfram|Alpha will produce a list of some of the brightest as seen from Earth. Let’s compare the properties of the galaxies NGC 7544 and the nearby M 83 (well, only 15.78 million light years away). Wolfram|Alpha provides information including their approximate distance from Earth, Hubble type, apparent magnitude, equatorial position, and position in the sky and visibility from your current location. Keep in mind that object distances may not be available for all objects; one of the great mysteries of astronomy is that distance is notoriously difficult to determine except in special cases. More »
Whether you are an astronomy student or just interested in learning more about those points of light in our sky, Wolfram|Alpha contains star data that will help you get started and understand what you’re seeing up there. Wolfram|Alpha not only charts the stars from your location, but offers detailed information including their distance from Earth, color, size, and much more.
To figure out which stars are the most visible to you, simply enter “10 brightest stars“. The query’s results indicate that the brightest stars as seen from Earth are the Sun, Sirius, Canopus, Arcturus, Rigel Kentaurus A, Vega, Capella, Rigel, Procyon, and Betelgeuse. Pods show comparisons of the stars’ size, their equilateral locations, and their locations in the current sky (not necessarily the night sky—unless you specify a time/location, Wolfram|Alpha assumes the current time from your current location).
Wolfram|Alpha contains a wealth of astronomy data on many areas of our universe, such as objects within our solar system and in the deep sky, constellations, and computational astronomy, making it a handy resource for astronomers, students, and hobbyists. Some of the most intriguing space activity takes place right here at home, inside of our own solar system. Wolfram|Alpha makes computations and explores properties and locations for objects and events in our solar system, such as the sun, planets, planetary moons, minor planets, comets, eclipses, meteor showers, sunrise and sunset, and solstices and equinoxes. You can query any one of these objects or phenomena, and learn information such as their position in the sky relative to your location, size, or distance; their next occurrence; and much more.
Wolfram|Alpha automatically assumes your geographic location based on your IP address, which is handy when querying for the time and location of an upcoming sky event. For instance, a quick “lunar eclipse” query in Wolfram|Alpha tells us that, for our location in Champaign, Illinois, the next one will occur on August 5, 2009 at 7:38pm U.S. Central Daylight Time and will be penumbral, which means the moon will enter the Earth’s penumbra (the outer part of its shadow), resulting in an apparent darkening of the moon. A penumbral eclipse is often hard to see because the penumbra isn’t very dark.