Sunspots are one way we can track the activity of the Sun. There have been fewer sunspots than usual in recent years, and that may point toward an historic solar minimum. 

Sunspots are dark patches that occasionally appear on the surface of the Sun. They aren’t actually dark. If you could see a sunspot by itself it would appear bright red, but since sunspots are about a quarter as bright as the rest of the Sun, they appear as dark regions. Since the early 1600s astronomers have counted the number of sunspots over the years, and we’ve noticed a few patterns. One is that sunspot counts vary between maximum and minimum over an 11-year period. There are other patterns as well, such as the Gleisberg Cycle, which lasts 80 – 90 years.

Directly recorded sunspot counts over the years. Credit: Robert A. Rohde (CC BY-SA 3.0)

There are times when the pattern seems to break down, and the Sun can enter into an extended period of little sunspot activity. The most famous is the Maunder minimum of the 1600s. While we don’t have direct sunspot counts before the early 1600s, we can look at the levels of carbon-14 as measured from tree rings. Since carbon-14 levels have a good correlation to sunspot counts, we can get a handle on a much longer history of sunspots. It turns out there have been other periods of minimum activity, such as the Wolf minimum of the 1300s. In general, the sunspot activity of the Sun in recent centuries is somewhat higher than most, except for a period during the middle ages known as the Medieval maximum.

For the past couple of cycles the sunspot maximums have been lower than usual. The pattern is similar to the early stages of the Dalton minimum in the early 1800s, which has raised the question of whether we are entering a period of reduced sunspot activity. This may also have some effect on global temperatures. The Dalton minimum saw a brief period of colder temperatures, and the Maunder minimum was marked by the “little ice age” where Europe and North America experienced a colder period. It should be stressed that connections between sunspot activity and global temperatures is still not clear. The Dalton cold period for example, saw the explosion of Mount Tambora, which would also contribute to cooler temperatures.

What is clear is that periods of minimal sunspot activity are notoriously difficult to predict. While the pattern of the past few cycles has similarities with the early Dalton minimum, it could also be a small fluke before a return to cycles as normal.

The post Year Of The Quiet Sun appeared first on One Universe at a Time.

Given the rising popularity of One Universe at a Time, I’ve had to upgrade my hosting level. If you’re reading this, then the upgrade has already happened.  Everything should be the same with one exception, and that is the site is now working on https rather than old school http. Now you can read about the universe with encrypted security. There shouldn’t be any glitches, but if you notice anything, please let me know.

I would like to note that this switch to https and to a faster, more reliable plan has been possible thanks to you. So thanks to all of you who read, comment and share my posts across the internet. And a very special thanks to those of you who generously support this site on Patreon.

I am humbled by your support, and will continue to strive for honest and clear science writing.

The post Did You Feel That? appeared first on One Universe at a Time.

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This morning a Universe Today video on the size of the universe was released, which I helped write. Then in the afternoon I was on Connections with Evan Dawson, where we talked about the latest news about the comet Churyumov-Gerasimenko, science communication and a range of other astronomical topics. You can check out that interview here.

For those listeners who have tracked down my website, because of all this media attention,welcome! Feel free to browse, or check out the site index for a list of posts. There’s nearly 600 posts here, so there is plenty of reading to be had.

The post Media Day appeared first on One Universe at a Time.

There’s no new post today because I’ve been transferring things to the new server.  If you’re reading this, then it has worked.  There will likely be some changes due to the transfer, but overall nothing should change.  I’ll return to the regularly scheduled programing soon.

The post Welcome to the New Server appeared first on One Universe at a Time.

You may have heard about NASA’s budget woes and how that impacts most of their outreach programs.  It means we not only lose programs such as the annual +NASA Jet Propulsion Laboratory open house and +CosmoQuest, but also programs such as the one I worked with this past weekend.  It is a project called NASA Science and Technology on the Family Calendar.It is a collaboration between +NASA, +Rochester Institute of Technology, and the Rochester Museum and Science Center where kids get to develop demonstrations and displays for their science center.  It’s a great example of bottom up (rather than top down) science outreach.  Science driven by the questions and interests of kids themselves, rather than being dictated by teachers and scientists.The overall topic for this weekend’s project was “Earth From Space”.  So teams looked at environmental changes, natural disasters, remote imaging and other topics related to space-based observations of Earth.  One team wanted to release a weather balloon to take pictures from space.  We didn’t have the budget for a released balloon, but we could do a tethered one.  As you can see, they got some pretty cool pictures of downtown Rochester.This particular project wasn’t a huge grant, but there are hundreds like it across the country, and they are all at risk with the budget cuts.  Most kids don’t live near JPL, and losing the annual open house won’t mean much to them.  But children all over the country will lose opportunities such as this one due to current cut backs.Hopefully we can change that trend.

The post NASA Outreach appeared first on One Universe at a Time.

Most of the solar system lies within a flat plane.  The plane in which the Earth orbits is known as the ecliptic, and the orbits of the other seven planets are all within a few degrees of the ecliptic. The ecliptic is usually defined as the path the Sun traces through the sky in a given year.  Because of the orbit of the Earth about the Sun, the Sun appears to move along the ecliptic during the year.  Because the Moon and other planets all orbit within a few degrees of this plane, you can always find the Sun, Moon and planets in the general region of the ecliptic. 

The reason for the planets lying in this common plane has to do with the way planetary systems form.  As a cloud of gas and dust begins to collapse into a star, its rotation causes it to flatten into a disk.  This gives rise to a protostar at the center of the cloud, with a protoplanetary disk surrounding it.  We see such protoplanetary disks in stellar nurseries, such as the Orion nebula.

As planets begin to form within the protoplanetary disk, much of the material is either captured by planets or scattered to the outer regions of the system (such as the Oort cloud).  But the planets don’t capture all the material.  There remain asteroids and meteorites, and even smaller grains of dust.  Like the planets, much of this dust lies within the plane of the solar system.  Collisions between asteroids, cometary dust and other processes also contribute to this dust.

We can see this dusty plane at during the Spring and Fall, when the ecliptic is titled far from the horizon.  It can only be seen in dark skies, either before sunrise or after sunset.  It is more commonly observed before sunrise as a dim glow, which is why it is sometimes called the false dawn.

It is more commonly known as the zodiacal light, because it is seen along the ecliptic, and the plane of the ecliptic is also the region in which the zodiac constellations lie.  If you ever catch a glimpse of this zodiacal light, you’ll have seen the dust of our solar system.

The post False Dawn appeared first on One Universe at a Time.

I’ve turned off WordPress comments for now.  I just don’t have the time to delete 30 spam messages a day, and since comments aren’t too active at the moment, it’s easier to just shut them down.  You can still comment from Google+, Facebook, or Disqus.  I may open WordPress comments back up in the future, but I’ll need to find a way to manage spam first.

The post Spam and More Spam appeared first on One Universe at a Time.

The post First World Problems appeared first on One Universe at a Time.

It’s now been a week since I started this website, so now that the dust has settled a bit I’d like to ask a few questions.  Specifically I’m interested in what format or tools you might find particularly useful.

Is there a comment system you like to see on a blog?  Do you like seeing “follow me on …” links or do you find them annoying.  Is it useful to have related posts, etc.

As I mentioned in my first post, I’m most familiar with Google+, and that has its own community.  I’m hoping this site will draw a wider readership, so I’d like to make the site as useful as possible with few annoyances if I can help it.

So any suggestions you more experienced blog readers have would be greatly appreciated.

The post Blog Questions appeared first on One Universe at a Time.