Perseid Meteor Shower - August 11-12, 2000

The Perseid Meteor Shower peaks the night of Friday, August 11th until early morning of Saturday, August 12th. During the hour before sunrise, astronomers predict as many as 40-50 meteors may be visible under clear, dark skies. But for most of the evening, observation of the Perseids will be almost completely washed out by the brilliant light of the waxing gibbous Moon. [On August 12th, the Moon does not set until 3:47 a.m., an hour-or-so before morning twilight, beginning at 5:51 a.m. (Note: all times are EDT for Washington, D.C.)]

Three "Ps" will help find the direction from which the meteors appear to radiate: Polaris - Perseus - Pleiades. The radiant (or point of origin) for the meteor shower is in the constellation Perseus, located about midway between the North Star Polaris in the constellation Ursa Minor, and M45, the Pleiades star cluster in the constellation Taurus, the Bull. More simply, look toward the northeastern sky.

Meteors, also known as "shooting-" or "falling stars," are streaks of light caused by small pieces of solar system debris, usually sand-sized particles, which vaporize while colliding at great speed (up to 40 miles per second, or 64 km per sec.) with the Earth's atmosphere at an altitude of approximately 40-60 miles (60-100 kilometers). Annual "meteor showers" (up to several meteors per minute) occur every year at about the same time when the Earth's orbit crosses the orbits of comets (as a comet evaporates, the orbital path of the comet becomes filled with debris from the comet's nucleus). Most annual meteor showers are named for the constellation from which the meteors appear to radiate.

Earth at Aphelion

The shape of the Earth's orbit around the Sun is an ellipse (although it is almost perfectly circular); the point at which the Earth is farthest from the Sun is known as aphelion. The Earth reaches aphelion on 04 July 2000. Food for thought: if the Earth is farthest from the Sun, then why is it Summer in the northern mid-latitudes? The answer lies in the annual cycle of change in the apparent path of the Sun across the sky (refer to "Summer Solstice" below).

Summer Solstice

The Summer Solstice occurs at 9:48 p.m. on 20 June 2000. On this date, the Sun reaches the northernmost line of latitude (the Tropic of Cancer, 23.5 degrees N) where the midday Sun is at the zenith (the imaginary point directly overhead). At northern mid-latitude locations, the midday Sun reaches its maximum altitude (annually) and the duration of insolation (number of hours of daylight) is greatest. For example, in Washington, D.C. the midday Sun will reach an altitude of 74.5 degrees above the horizon and there will be nearly 15 hours of daylight. Also, the Sun rises farthest to the north of east (to the far left of the Washington Monument in the accompanying photograph) and sets farthest to the north of west than at any other time of year.

Earliest Sunrise/Latest Sunset

Washington, D.C. - From June 10-17, the Sun rises at 5:42 a.m. EDT, the earliest time of sunrise all year. From June 20 to July 5, the Sun sets at 8:37 p.m. EDT, the latest time of sunset all year.

By jimminy, it's time to say, "Bye, Gemini!"

Ever heard the old expression, "by jimminy?" Originally, the phrase meant something like, "with any luck," derived from the mythological association between the Gemini Twins and good luck. By the middle of June, your luck has run out as the constellation Gemini (No. 3, FCPS Starfinder) slips below the Western horizon shortly after 9 p.m.

Hurricane Awareness Week

Due to the rapid population growth in hurricane-prone coastal areas and the recent devastating effects of hurricane-related inland flooding in the mid-Atlantic states, the National Weather Service and the Federal Emergency Management Agency have joined forces to declare May 12-20, 2000 "National Hurricane Awareness Week" (in Virginia, Hurricane Awareness Week is June 4-10).

1 June is the beginning of Tropical Atlantic hurricane season (ending 30 NOV). What's the seasonal outlook this year? La Nina usually means an active hurricane season in the Tropical Atlantic Ocean. For a second opinion, visit the Colorado State University Hurricane Forecast Web page for reknowned hurricane forecaster Dr. William M. Gray's prediction.

First 90-Degree Day

Sunday, 07 May the high temperature at Reagan National Airport (DCA) reached exactly 90°F--the first 90-degree day for the year 2000 (May 19 is the average date of the first 90-degree day at DCA; September 12 the last). For more information about Summer weather in the Washington, D.C. area, visit the WeatherNet4 Summer Statistics Web page.

Space Day/Cyber Space Day

Thursday, 04 May 2000, Washington, D.C. The fourth annual Space Day, which celebrates the achievements, benefits, and opportunities in the human exploration of outer space, kicks off at the Smithsonian Institution National Air and Space Museum. Spearheading the festivities is the event's spokesperson, NASA astronaut and former U.S. Senator John H. Glenn Jr. Cyber Space Day is a live, interactive Webcast (archives of past Webcasts also available online). The theme for Space Day/Cyber Space Day 2000: "Living and Working in Space."

Sandburg Planetarium "Open House"

Tuesday, 2 May from 10:30 - 11:00 a.m., there will be a special "Open House" program at the Sandburg Planetarium. Among other topics, the cross-curricular Grade Level 7 English sky poetry unit and the Grade Level 8 Science astronomy unit (including upcoming class visits to the planetarium in May) will be highlighted. In addition, there will be a quick tour of the late Spring/early Summer night skies. Parents are invited to attend the program to see firsthand how this extraordinary resource enriches the instructional program at Sandburg Middle School (as well as the other schools in the Sandburg Planetarium Service Area).

Early May Planetary Conjunction

"The long-awaited, though invisible, conjunction of five planets occurs during the first two weeks of May. Mercury, Venus, Mars, Jupiter, and Saturn all lie on the far side of the Sun as seen from Earth, spanning a 27° stretch of sky on May 3. The Moon is also included in the collection. Two weeks later, on May 17, the six bodies minus the Moon stretch out across only 19.5° of the sky.

The grouping cannot be seen because the Sun is in the way. In reality, the planets, as always, lie far apart--this grouping is merely a line of sight effect, but nonetheless unusual. It is sure to spark some media attention."

(Excerpted from The Sky Show in May, by Martin Ratcliffe and Alister Ling, courtesy Astronomy magazine, Kalmbach Publishing.)

HST 10th Anniversary

25 April 2000, celebrate the 10th anniversary of the deployment of the Hubble Space Telescope by visiting the HST's Greatest Hits Picture Gallery. For basic information about the Hubble Space Telescope, read the STSI Hubble Primer. Track the current location of HST (courtesy NASA Liftoff to Space Exploration).

31 March 2000 - HubbleSite--the new public interface for casual visitors and explorers--debuts, including a new 10th Anniversary component: The HST - A Decade of Discovery. Good stuff! (Note: the Space Telescope Science Institute Home Page will continue as the "front door" for academic users.)

National Sky Awareness Week

Every year, Easter occurs on the first Sunday after the first Full Moon after the Spring Equinox (e.g., the Spring Equinox occurred on 20 March 2000, the next Full Moon occurred on 18 April, and Easter is Sunday, 23 April). Well, usually. For more details, visit The Date of Easter Web page, including the Easter Calculator.

Last Freeze

On average, the last frost in Washington, D.C. occurs sometime between April 10-20 (April 20-30 for the northern and western suburbs). For more information about Spring weather in the Washington, D.C. area, visit the WeatherNet4 Washington Spring Statistics Web page. With the onset of warmer temperatures, it won't be long 'til our first 90-degree day!

Astronomy Day/Week (and Space Day)

Saturday, 8 April, the Astronomical League and Sky & Telescope magazine encourage you to celebrate Astronomy Day by participating in public activities in your locality (e.g., Smithsonian National Air and Space Museum Astronomy Fair & Evening Star Gazing, or NOVAC Observes Astronomy Day). Astronomy Week runs from April 3 to 9. For more information, go to S&T's Astronomy Day Web site. Looking ahead to May, Space Day is Thursday, 04 May 2000.

Spring Forward...

At 2:00 a.m. on Sunday, 2 April set your clocks forward one hour to begin "Daylight Saving Time" (EDT). Something of a misnomer, we merely shift the increasing daylight hours from the morning to the evening. Daylight Saving Time begins on the first Sunday in April (Spring forward...) and ends on the last Sunday in October (...Fall back).

April is National Poetry Month

Celebrate National Poetry Month and increase your sky awareness by reading some of Carl Sandburg's sky-related poetry, or by reading Carl Sandburg Middle School student-authored sky-related poetry.

Tornado Preparedness Day

Virginia Governor Gilmore has declared Tuesday, 28 March 2000, "Tornado Preparedness Day." [In MD/DC, "Severe Weather Awareness Week" is April 23-29, 2000 (coincident with National Sky Awareness Week).] Visit the NOAA National Weather Service Office of Meteorology Severe Weather Awareness Web site for an online Tornado Preparedness Guide, including information regarding tornado safety in schools. Preparedness Guides for other weather hazards are available online also. A GUIDE TO DEVELOPING A SEVERE WEATHER EMERGENCY PLAN FOR SCHOOLS, by Barbara McNaught Watson, Warning Coordination Meteorologist with the NWS Baltimore/Washington Forecast Office, is a "must read" for school safety planners.

March Equinox

The March Equinox occurs at 2:35 a.m. EST on 20 March 2000. The word equinox literally means "equal nights," referring to either of two times of the year when the Sun crosses the plane of the Earth's Equator and day and night are of equal length, that is, about March 21 and September 22. The Sun rises exactly due east (just to the right of the Washington Monument in the accompanying photograph) and sets due west. The March Equinox is the beginning of astronomical Spring in the Northern Hemisphere and Autumn in the Southern Hemisphere (in the Northern Hemisphere, meteorological Spring is MAR, APR, and MAY).

If you know what a conjunction is, ...

...grammatically speaking, then you know what a conjunction is, astronomically speaking. The dictionary defines a conjunction (ken-jungk-shen) as:
1. the act of joining together or the state of being joined together.
2. a word used to connect words, phrases, or sentences. And, but, or, and if are conjunctions.
3. Astronomy, the apparent meeting of two or more planets or other heavenly bodies at the same celestial longitude.

March 7-10, the best evening conjunction of the year occurs as the planets Mars, Jupiter, and Saturn and the waxing crescent Moon appear to come together in a short, straight line in the western sky shortly after sunset. Twilight is a good time to go planet-watching, as the planets are the first objects (other than the Moon) to appear in the sky as daylight fades to darkness. The Moon appears slightly below the line of planets because its orbit is inclined approximately five (5) degrees with respect to the plane of the Earth's orbit around the Sun. Each night, the Moon will appear to slip from right to left along the line of planets, beginning with Mars on 8 March. (Graphic courtesy Astronomy magazine, Kalmbach Publishing.)

March: In Like a Lion; Out Like a Lamb.

	You've probably heard the old saying, "March comes in like a lion and goes out like a lamb."
Usually, this saying is used to describe typical March weather: in the beginning of March, the weather is wild; by the end of March, the weather is mild. But this modern weather proverb actually originates from astronomy: in the late-February/early-March night skies, Leo, the Lion (No. 5, FCPS Starfinder) is rising in the East ("coming in") at the same time that Aries, the Ram (lamb) is setting in the West ("going out").

Groundhog Day, 02 February 2000

According to legend, if Phil sees his shadow on February 2nd, then there will be six more weeks of winter weather; if he doesn't see his shadow, then there will be an early Spring. Hogtivities provides a list of activities for celebrating Groundhog Day with younger students.

Total Lunar Eclipse

Weather permitting, a spectacular total eclipse of the Moon will be visible over the Americas and Western Europe beginning during the late evening hours of 20 JAN 2000 and ending in the early morning hours of the 21st. Totality will be especially dramatic in North America, where the rusty-red Moon will pass high overhead in the crisp, clear winter sky. It's perfectly safe to view lunar eclipses, so teachers can feel comfortable telling their students to watch.

Total Lunar Eclipse of January 20-21, 2000

Event	Time (EST)
Moon enters penumbra	09:03 p.m.
Moon enters umbra	10:01 p.m.
Moon enters totality	11:05 p.m.
Middle of eclipse	11:44 p.m.
Moon leaves totality	12:22 a.m.
Moon leaves umbra	01:25 a.m.
Moon leaves penumbra	02:24 a.m.

Quadrantids Meteor Shower

Peak activity should occur at 1 a.m. EST on the night of January 3-4, 2000. The radiant (the point from which the meteors appear to radiate) is located in the constellation Bootes, near the handle of the Big Dipper (Ursa Major). Dress warmly!

December Solstice

The Sun reaches the December Solstice at 2:44 a.m. EST on 22 DEC 1999, marking the beginning of astronomical winter in the Northern Hemisphere and summer in the Southern Hemisphere (in the Northern Hemisphere, meteorological winter is DEC, JAN, and FEB). On this date, the Sun rises to the farthest south of east (to the far right of the Washington Monument in the accompanying photograph) and sets to the farthest south of west than at any other time of year.

Coincidentally, on DEC 22nd the Moon reaches its closest point to the Earth all year (perigee), a few hours after the December solstice and a few hours before the Full Moon. Ocean tides will be exceptionally high and low that day.

Disclaimer - In response to a widely circulated, but highly inaccurate e-mail message regarding the extraordinary apparent brightness of the DEC Full Moon, allegedly caused by the coincidence of the December solstice, perigee (the point at which the Moon is closest to the Earth), and the Full Moon, we offer the following disclaimer:

While it is true that the coincidence of events is somewhat rare, the fact of the matter is the apparent size and brightness of the DEC Full Moon will be imperceptibly different than any other Full Moon during the year. The accuracy of the e-mail message has been refuted by Geoff Chester, Public Information Officer at the U.S. Naval Observatory in Washington, D.C. Get a second opinion from the editors of Sky & Telescope magazine (scroll down to the 15 DEC article, "Brightest Moon in 133 Years?").

December's Gems

The Geminid meteors peak on the night of December 13-14. Under ideal conditions, as many as 75 meteors per hour might be seen. The waxing crescent Moon sets around 10 p.m. on the 13th; begin watching immediately afterwards because the shower's radiant (near the bright star Castor in the constellation Gemini) is already fairly high in the sky by then. The higher a shower's radiant, the more meteors it produces all over the sky. [Paraphrased from "Calendar Notes," p. 115, Sky & Telescope, DEC 1999.] For more information, visit SKY Online's Meteor Page.

ET, Phone Home!

Mission Update: 04 DEC '99 - No contact has been made yet with Mars Polar Lander and DS2 probes during first 12 hours after landing. Attempts continue with follow-up opportunities.

Mars Polar Lander - Searching for Water on Mars. Remember the excitement when the Mars Pathfinder/Sojourner landed on 04 JUL 1997? Well, it's Deja Vu all over again (as Yogi Berra would say)! On 03 DEC 1999, the Mars Polar Lander is scheduled to land near the south pole of Mars. Sights and sounds from the surface of Mars will be accessible in near-real-time (given transmission delays between Mars and Earth) via the preceding Web site. Stay tuned....

Hurricane Season Ends

Hurricane Season in the Tropical Atlantic Ocean ends NOV 30th. As predicted, it was an active season.

Leonids Meteor Storm?

"On the 17th or 18th of November there is the potential for a Leonid meteor storm, the likes of which have been seen only a few times per century." (Calendar Notes, p. 114, Sky & Telescope magazine, November 1999.) Plan to watch on the night of November 17-18 after 11 p.m. or midnight when the constellation Leo rises above the eastern horizon. To find Leo, refer to the January FCPS Starfinder (the 9 p.m. January sky is the same as the 1 a.m. November sky); note the bright star Regulus, the heart of the lion (Letter "M") rising above the eastern horizon. For more information, visit SKY Online's Meteor Page or read the NASA Space Science News article entitled, "Leonids in the Crystal Ball - Most experts agree that 1999 is a likely year for a Leonids meteor storm."

Next month, December's GEMs (the Geminids meteor shower)....

Winter Weather Awareness Week

In Virginia, Winter Weather Awareness Week is November 14-20, 1999. Visit the Weather Channel Project SafeSide Web site for a free collection of cross-curricular lesson plans and activities that teach students how to prepare for severe weather and natural hazards, including winter weather (as well as tornadoes, lightning, floods, extreme heat, hurricanes, and earthquakes). Designed for grades 4-12.

Mercurian Transit

On Monday, 15 November 1999, the western Hemisphere will be treated to an astronomical event unseen for 25 years. On that day the tiny planet Mercury will pass between the Sun and the Earth--an event known as a "transit." The event starts at 1:00 p.m. PST (4:00 p.m. EST) and will be Webcast live by the Exploratorium. The famous 36" refractor telescope at Lick Observatory will be used to bring you the images of the transit. The transit will last about one (1) hour. Archives of the transit will be posted for those who cannot experience it live.

First Frost?

Definitely! Widespread frost observed on the morning of Thursday, 04 November 1999.

2 a.m., Sunday, 31 October 1999 - Daylight Saving Time Ends

Remember the mnemonic: Spring forward; Fall back? On the last Sunday in October, clocks are set back one hour to return to Standard Time. Notice how much earlier sunset seems to be! Sure sign that Winter is coming: the number of daylight hours is decreasing. By the time of the December Solstice (22 DEC), there will be only nine hours and 17 minutes (9h17m) of daylight--the fewest hours of daylight all year!

First Frost?

Slightly earlier than average, on Monday, 25 October we observed the first frost at the Sandburg Center for Sky Awareness. Well, it was actually frozen dew but close enough! For more information about Fall weather in the Washington, D.C. area, visit the WeatherNet4 Washington Fall Statistics Web page. With the onset of frosty cold temperatures, it won't be long 'til the first snowfall! In the meantime, make artificial snow by visiting Snowflake Designer, a very cool (pun intended) Shockwave multimedia Web site.

September Equinox

The equinox occurs on 23 September at 7:30 a.m. EDT, marking the beginning of astronomical Autumn in the Northern Hemisphere and the start of astronomical Spring in the Southern Hemisphere. The Sun rises exactly due east (just to the right of the Washington Monument in the accompanying photograph) and sets due west, and day and night are approximately equal in duration. Note: meteorological Fall (SEP, OCT, NOV) begins 01 SEP.

Hurricane Season

Mid-September is the climatological peak of Tropical Atlantic hurricane season (witness Hurricane Floyd).

Say Goodbye to the 90s...

...in more ways than one! On average, September 12th is the last 90-degree day at Washington Reagan National Airport (DCA). For more information about Fall weather in the Washington, D.C. area, visit the WeatherNet4 Washington Fall Statistics Web page. With the onset of cooler temperatures, it won't be long 'til our first freeze which, in part, triggers leaf color to change.

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