Speaking of solar activity, a giant coronal hole opened up in the Sun’s northern hemisphere earlier this week, triggering auroras at high latitudes. Image made by the Solar Dynamics Observatory (SDO), via APOD. Click image to enlarge.

This is an interesting article on the SOHO website. The speeding of the internal plasma circulation is connected with the deepest solar minimum in a century.

One of the outstanding questions facing solar physicists is the origin of the solar magnetic cycle: What drives the 11-year sunspot cycle? We have just passed an extended and deep minimum, unlike any in the past 100 years. The late onset of the new solar cycle (#24) and the unusually deep minimum between cycles 23 and 24 took all experts by surprise, which suggests that there is a fundamental lack in our understanding of the origin of the solar activity cycle.

Image: Artist’s concept of the Sun’s meridional circulation, a large scale flow that transports solar plasma from the equator to the poles and back like a giant conveyor belt. Credit: Science@NASA

The Sun’s meridional circulation is a massive flow pattern within the Sun that transports hot plasma near the surface from the solar equator to the poles and back to the equator in the deeper layers of the convection zone, similar to a “conveyor belt”. The flow is rather slow, with typical speeds of 10-15 m/s (20 to 30 mph). The structure and strength of this meridional flow is believed to play a key role in determining the strength of the Sun’s polar magnetic field, which in turn determines the strength of the sunspot cycles. One class of dynamo models predicts that a stronger meridional flow produces weaker polar fields, whereas another class of models predicts stronger polar fields (and a shorter sunspot cycle) for the same flow. [more]

The new solar cycle antes up a massive CME for Fathers day. From SpaceWeather.com . . .

FATHER’S DAY BLAST: Consider it a Father’s Day gift … from the sun. This morning around 1 a.m. UT, magnetic fields on the sun’s eastern limb became unstable and erupted, producing one of the most spectacular explosions of the year. NASA’s Solar Dynamics Observatory recorded the action:

The explosion did not cause a solar flare (a flash of electromagnetic radiation) but it did hurl a massive cloud of magnetized plasma into space. Because of the blast site’s location on the eastern limb, the cloud will not hit Earth. There won’t be any geomagnetic storms or auroras.

Why would that be significant? Well, it would allow for a full 4PI (360×360°) view of the sun. The animated movie of the sun on STEREO’s Website currently has a gap in the coverage of the sun. The spacecraft are in a heliocentric orbit drifting away from the Earth, one leading and one lagging. This diagram shows the current position of spacecraft A (ahead) and B (behind). The scale is in astronomical units, the average distance between the earth and sun.

Sun-monitoring instrumentation on spacecraft like SOHO and STEREO have gone a long way in discovering what makes the sun behave in mysterious ways. Also, the data coming back (when not intentionally distorted by the IPCC, the CRU or NASA’s James Hansen) can be used to chart the relationship between solar activity and global climate.

Solar activity has been increasing in recent months. This extraordinary video depicts a “plasma ring” coronal mass ejection (CME) as captured by SOHO. Watch the lower right corner for the ring ejection.

These images are just astounding . . .

April 21, 2010: Warning, the images you are about to see could take your breath away.

At a press conference today in Washington DC, researchers unveiled “First Light” images from NASA’s Solar Dynamics Observatory, a space telescope designed to study the sun.

“SDO is working beautifully,” reports project scientist Dean Pesnell of the Goddard Space Flight Center. “This is even better than we could have dreamed.”

Launched on February 11th from Cape Canaveral, the observatory has spent the past two months moving into a geosynchronous orbit and activating its instruments. As soon as SDO’s telescope doors opened, the spacecraft began beaming back scenes so beautiful and puzzlingly complex that even seasoned observers were stunned.

Be sure to click on the image above to view full-size and then go to the SDO Website.

Or should it be SUN-IMPACTOR COMET? I saw this yesterday on SpaceWeather.com:

SUNGRAZING COMET: Today, the sun had a comet for breakfast. The icy visitor from the outer solar system appeared with no warning on April 9th and plunged into the sun during the early hours of April 10th. One comet went in, none came out. The Solar and Heliospheric Observatory (SOHO) had a good view of the encounter.

The comet was probably a member of the Kreutz sungrazer family. Named after a 19th century German astronomer who studied them in detail, Kreutz sungrazers are fragments from the breakup of a giant comet at least 2000 years ago. Several of these fragments pass by the sun and disintegrate every day. Most are too small to see but occasionally a big fragment like today’s attracts attention.

This has been an active year for big, bright sungrazers. There was one on Jan. 4th, one on March 12th, and now one today. Normally we see no more than 3 or 4 bright ones in a whole year; now we’re seeing them almost once a month. It could be a statistical fluctuation or, maybe, a swarm of Kreutz fragments is nearing perihelion (closest approach to the sun). Stay tuned for doomed comets!

Click on the thumbnail image for full-size movie.

It looks like the solar activity is starting to increase. This is the first day in a while where there are three sunspots visible on the Earth-facing side of the sun. These images are from the SOHO spacecraft. The left panel is the visible light snapshot and the right panel is energy being emitted in a narrow band of ultraviolet. You can’t see UV, but it’s common knowledge that it is a major cause of skin damage.

Just how solar activity affects the climate isn’t well understood, but there is correlation between sunspot numbers and the climate.

I don’t know about you, but I am sure there are a lot of Americans rooting for warmer weather tonight. That includes us, even though we’re California weather wimps according to Breda.

Tomorrow night, when the full moon rises over North America, it will be a “blue moon,” the first such occurrence to fall on December 31st since 1990.

The modern definition for “blue moon” is the second full moon to occur within a calendar month and tomorrow’s full moon will indeed be the second to occur in the month of December, 2009.

Cartoon Image courtesy of NASA.

But wait - there’s more to the blue moon phenomenon . . .

From NASA

Most months have only one full Moon. The 29.5-day cadence of the lunar cycle matches up almost perfectly with the 28- to 31-day length of calendar months. Indeed, the word “month” comes from “Moon.” Occasionally, however, the one-to-one correspondence breaks down when two full Moons squeeze into a single month. Dec. 2009 is such a month. The first full Moon appeared on Dec. 2nd; the second, a “Blue Moon,” will come on Dec. 31st.

This definition of Blue Moon is relatively new.

. . .

The modern definition sprang up in the 1940s. In those days, the Farmer’s Almanac of Maine offered a definition of Blue Moon so convoluted that even professional astronomers struggled to understand it. It involved factors such as the ecclesiastical dates of Easter and Lent, and the timing of seasons according to the dynamical mean sun. Aiming to explain blue moons to the layman, Sky & Telescope published an article in 1946 entitled “Once in a Blue Moon.” The author James Hugh Pruett cited the 1937 Maine almanac and opined that the “second [full moon] in a month, so I interpret it, is called Blue Moon.”

That was not correct, but at least it could be understood. And thus the modern Blue Moon was born.

. . .

The modern astronomical Blue Moon occurs in some month every 2.5 years, on average. A Blue Moon falling precisely on Dec. 31st, however, is much more unusual. The last time it happened was in 1990, and the next time won’t be until 2028.

Being a long-time astronomy enthusiast, I am very glad that the Hubble Space Telescope is busily producing magnificent images such as this one of Barred Spiral Galaxy NGC 6217, seen on today’s Astronomy Picture of the Day:

From the HST website:

For the past three months, scientists and engineers at the Space Telescope Science Institute and Goddard have been focusing, testing, and calibrating the instruments. Hubble is one of the most complex space telescopes ever launched, and the Hubble servicing mission astronauts performed major surgery on the 19-year-old observatory’s multiple systems. This orbital verification phase was interrupted briefly July 19 to observe Jupiter in the aftermath of a collision with a suspected comet.

Hubble now enters a phase of full science observations. The demand for observing time will be intense. Observations will range from studying the population of Kuiper Belt objects at the fringe of our solar system to surveying the birth of planets around other stars and probing the composition and structure of extrasolar planet atmospheres. There are ambitious plans to take the deepest-ever near-infrared portrait of the universe to reveal never-before-seen infant galaxies that existed when the universe was less than 500 million years old. Other planned observations will attempt to shed light on the behavior of dark energy, a repulsive force that is pushing the universe apart at an ever-faster rate.

Click on the image above to enlarge.

Scientists don’t yet know enough to say with certainty what the source of the Martian methane is, but this artist’s concept video depicts several possibilities. In this video, conjecture is offered for several possibilities. First, meteoric debris reacting with atmospheric particles possibly generating methane, next comet and meteor impacts creating chemical reactions resulting in methane production. Third, subsurface water, carbon dioxide and the planet’s internal heat combine to release methane, and, finally, living microbes actively producing methane as a waste product.

Whatever the process is, there is clear evidence that Mars is ‘farting’ methane.

Today is Solstice, the shortest day in the Northern Hemisphere - according to the solar ephemeris for our location, the length of our day will be approximately nine hours and fifty-four minutes.

The graphic below is taken from a very interesting website, Archaeoastronomy.com. On their website, you can learn about Equinoxes, Solstices and Cross Quarters which are moments shared planet-wide, defined by the earth’s tilt and the sun’s position on The Ecliptic along 45° arcs.

This neat graphic is put into motion on Archaeoastronomy.com.