TAG: Astronomy
July 14, 2011–

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 »

June 7, 2011–

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:

March 31, 2011–

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.

February 7, 2011–

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.

October 22, 2010–

Wolfram|Alpha has many trillions of pieces of data, many of which are facts about people, places, and things. All of this knowledge is built upon a computational engine that allows us to mash up topic areas and do impressive, if not outrageous, computations. In honor of it being Friday, we’ll share a few fun facts to get your mind curious about what else is waiting to be discovered within Wolfram|Alpha.

Fact: Your Halloween Jack-o’-lantern has 40 chromosomes.

Fact: There are 4.3 x 10^6 calories in one short ton of Snickers.

Fact: Lassoing the Moon from Earth will require about 239,200 miles of rope on average!

Fact: 36 degrees was the high temperature in New York City on the day Justin Bieber was born.

Fact: On April 1, 1976, just 47 years after Louis Marx popularized the yo-yo, Apple Computer was created—no joke!

These are just few of the fun facts highlighting data areas such as nutrition, species, science, weather, history, and events. What fun facts have you discovered in Wolfram|Alpha?

September 22, 2010–

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 »

August 5, 2010–

Here at Wolfram|Alpha we’re always asking questions and seeking answers in an effort to make all of the world’s knowledge computable and understandable by everyone (big or small).

We’ve put together a short list of common questions asked by preschool- and kindergarten-aged children that can be answered with Wolfram|Alpha. We hope these examples inspire your child to dream up more!

Is the Moon bigger than the Earth? Ask Wolfram|Alpha to compare “size of earth, size of moon”, and you’ll discover numerical and graphic size comparisons showing that the Earth is indeed larger than the Moon.

Chances are your little artists will discover the answer to this question on their own, but they can try asking Wolfram|Alpha what color they get when they “mix red and blue”?

Whether it’s because they’re excited about the party or just turning a year older, the birthday countdown is always on! Simply ask Wolfram|Alpha about the date of the child’s upcoming birthday, such as “October 8 2010”, to learn the number of days, weeks, or months until the big day.
More »

August 2, 2010–

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 »

May 20, 2010–

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 »

January 7, 2010–

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.

Today you can recreate the moment with today’s technology by typing “Jupiter” into Wolfram|Alpha.

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.

Type “Galilean moons” to find out more about them. Or for historical curiosity, try “January 7, 1610” and find out more about that day.

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 »

December 29, 2009–

Prior to releasing Wolfram|Alpha into the world this past May, we launched the Wolfram|Alpha Blog. Since our welcome message on April 28, we’ve made 133 additional posts covering Wolfram|Alpha news, team member introductions, and “how-to’s” in a wide variety of areas, including finance, nutrition, chemistry, astronomy, math, travel, and even solving crossword puzzles.

As 2009 draws to a close we thought we’d reach into the archives to share with you some of this year’s most popular blog posts.

#### April

Rack ’n’ Roll

Take a peek at our system administration team hard at work on one of the
many pre-launch projects.

#### May

The Secret Behind the Computational Engine in Wolfram|Alpha

Although it’s tempting to think of Wolfram|Alpha as a place to look up facts, that’s only part of the story. The thing that truly sets Wolfram|Alpha apart is that it is able to do sophisticated computations for you, both pure computations involving numbers or formulas you enter, and computations applied automatically to data called up from its repositories.

Why does computation matter? Because computation is what turns generic information into specific answers. Continue reading…

Live, from Champaign!

Wolfram|Alpha just went live for the very first time, running all clusters.

This first run at testing Wolfram|Alpha in the real world is off to an auspicious start, although not surprisingly, we’re still working on some kinks, especially around logging.

While we’re still in the early stages of this long-term project, it is really gratifying to finally have the opportunity to invite you to participate in this project with us. Continue reading…

#### June

Wolfram|Alpha Q&A Webcast

Stephen Wolfram shared the latest news and updates about Wolfram|Alpha and answered several users’ questions in a live webcast yesterday.

If you missed it, you can watch the recording here. Continue reading… More »

December 21, 2009–

We’re really catching the holiday spirit here at Wolfram|Alpha.

We recently announced our special holiday sale for the Wolfram|Alpha app. Now we are launching our first-ever Wolfram|Alpha “Holiday Tweet-a-Day” contest.

Here’s how it works.

From tomorrow, Tuesday, December 22, through Saturday, January 2, we’ll use Twitter to give away a gift a day. Be the first to retweet our “Holiday Tweet-a-Day” tweet and you get the prize! You can double your chances to win by following and playing along with Wolfram Research.

Start following us today so you don’t miss your chance to win with our Wolfram|Alpha “Holiday Tweet-a-Day” contest.

December 21, 2009–

When we launched Wolfram|Alpha in May 2009, it already contained trillions of pieces of information—the result of nearly five years of sustained data-gathering, on top of more than two decades of formula and algorithm development in Mathematica. Since then, we’ve successfully released a new build of Wolfram|Alpha’s codebase each week, incorporating not only hundreds of minor behind-the-scenes enhancements and bug fixes, but also a steady stream of major new features and datasets.

We’ve highlighted some of these new additions in this blog, but many more have entered the system with little fanfare. As we near the end of 2009, we wanted to look back at seven months of new Wolfram|Alpha features and functionality.

December 18, 2009–

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.

Type “redshift 6.3” into Wolfram|Alpha.

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 »

October 21, 2009–

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!

Starting close to home, you can examine the Moon:

More »

August 28, 2009–

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 »

August 13, 2009–

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).

August 3, 2009–

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.

July 8, 2009–

When it comes to astronomy data in Wolfram|Alpha, the sky is no limit! Hear what the developer working on Wolfram|Alpha’s astronomy features has to say about his role and the future of the project.

More interviews with Wolfram|Alpha team members are available here.

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May 1, 2009–

Although it’s tempting to think of Wolfram|Alpha as a place to look up facts, that’s only part of the story. The thing that truly sets Wolfram|Alpha apart is that it is able to do sophisticated computations for you, both pure computations involving numbers or formulas you enter, and computations applied automatically to data called up from its repositories.

Why does computation matter? Because computation is what turns generic information into specific answers.

To give an amusing example, every school child has at one time or another written a report on the moon, and they probably included the wrong figure for how far the moon is from the earth. Why wrong? Because the distance from the earth to the moon is not constant: it changes by as much as a mile a minute. If you ask Wolfram|Alpha the distance to the moon, it tells you not only the conventionally quoted average distance, but also the actual distance right now, which can at times be well over ten thousand miles off the average. The actual distance is a figure that can be arrived at only by computation based on the moon’s known orbital parameters. It’s rocket science, if you will.
More »