APRIL1 April Fools' Day; first day of Passover.
2 Good Friday; Pascua Florida Day; Jupiter at conjunction with the sun (and therefore unviewable); this day 25 years ago an anemometer atop Cannon Mountain in New Hampshire reported three wind gusts of 200 m.p.h. or more; this day in 1915 (it was the day before Easter), Philadelphia had 19 inches of snow.
3 Twenty-five years ago this day and next, greatest tornado outbreak on record: in one 24hour period, 14 states from Mississippi to New York (and onward into Canada) were struck by a total of 148 tornadoes, which killed 315 people and injured 5,500.
4 Easter; set clocks ahead ("spring forward") one hour at 2 a.m. Standard Time for start of daylight saving time.
5 This day in 1987, a storm ended after three days with up to 60 inches of April snow in Great Smoky Mountains National Park, on the border of Tennessee and North Carolina.
6 This morning in 1936, the morning after a tornado killed 216 people in Tupelo, Mississippi, another twister killed 203 in Gainesville, Georgia.
8 LAST QUARTER MOON, 10:51 p.m. EDT; Buddhists celebrate Buddha's Birthday, said to be in 566 B.C. or 563 B.C.
11 Orthodox Easter; this day in 1970, Apollo 13 launched off on what became the most harrowing U.S. mission in space.
12 Venus nearest the Pleiades star cluster (use binoculars) in west after nightfall; this day in 1961, Yury Gagarin became the first human to go into space.
13 Thomas Jefferson's Birthday.
16 NEW MOON, 12:22 a.m. EDT.
17 Islamic New Year—actually begins at the previous sunset, and only if the "young moon" (moon soon after new moon) is sighted. (Islamic New Year is based on a lunar calendar, and as such, its date steadily migrates backward through the solar calendar.)
19 Patriots' Day (Maine, Massachusetts); sun enters constellation Aries.
20 Venus nearest the star Aldebaran (a fairly sizable 7.3° away from it); sun enters astrological sign Taurus.
21 Queen Elizabeth II's Birthday; Baha'i faith's Festival of Ridvan starts (see article, page 12).
22 FIRST QUARTER MOON, 3:01 p.m. EDT; peak of Lyrid meteors—late after midnight and moonset tonight best time to look for these shooting stars, which will then be zooming out of the east; Earth Day.
23 St. George Day in Britain.
24 Mars at opposition (best time to observe it), rising opposite the sun and visible all night long.
25 Hubble Space Telescope deployed this day in 1990; Anzac Day in Australia and New Zealand.
27 Saturn at conjunction with sun (hence unviewable).
29 St. Catherine's Day.
30 National Arbor Day; FULL MOON, 10:55 p.m. EDT; May Eve.
MAY1 May Day (Beltane); Mars nearest to Earth and largest in telescopes; Mercury near Jupiter in east as morning twilight brightens, but very low; Zoroastrian holiday, Maidyoi Zaramaya, today through May 5 (see article, page 12).
2 Eta Aquarid meteors (debris of Halley's Comet) shoot out of southeast before dawn for next five days or so, but only a few might be seen in bright moonlight; Baha'i faith's Festival of Ridvan ends.
3 Venus now at about highest in west at sunset that it will get this spring, itself not setting until the hour before midnight (altitude declines only slightly by end of May).
4 This day in 1812, 12 inches of snow fell in Keene, New Hampshire.
5 Venus now becomes closer than the sun to Earth; Venus 0.7° from asteroid Ceres (telescopes and detailed finder chart needed to identify the asteroid; see May issue of Sky & Telescope magazine); Alan Shepard became the first American in space this day in 1961.
6 Halfway point of spring.
7 On this day in 1840, the Great Natchez Tornado struck Natchez, Mississippi, killing 317 people.
8 Truman Day in Missouri; LAST QUARTER MOON, 1:28 p.m. EDT
9 Mother's Day; Rogation Sunday.
11 Days of the Three Ice Saints, today through May 13; Mars now within 5° (half the width of your fist held out at arm's length) away from the bright star Spica—and closing a tiny bit more each evening.
13 Mercury just 0.62° from Saturn (a pencil at arm's length can hardly fit between them), but low in the east-southeast in the hour before dawn (try looking with binoculars); Ascension Day.
14 Sun enters Taurus; Skylab launched this day in 1973; on this day in 1896, Climax, Colorado hit-10°F.
15 Armed Forces Day; NEW MOON, 8:05 a.m. EDT; highest astronomical tides of year today; Gordon Cooper was launched in Faith 7, last of the Mercury program flights.
18 Eruption of Mt. St. Helens this day in 1980.
19 Jupiter at the innermost part of its orbit, closest to the sun in space (but still almost 500 million miles away), for the first time in 12 years.
20 Mars 3° due left of Spica at dusk.
21 Shavuot; sun enters astrological sign Gemini.
22 FIRST QUARTER MOON, 1:34 a.m. EDT, Astronomy Day.
23 Pentecost (also named Whitsunday, or, literally, white sunday, probably after the white robes worn by those newly baptized at this season); Declaration of the Bab (Baha'i faith).
24 Victoria Day in Canada.
25 Asteroid Juno at opposition (opposite the sun in the sky and visible all night).
29 Ascension of Baha'u'llah (Baha'i faith); Oak Apple Day (Restoration Day) in Britain.
30 FULL MOON, 2:40 a.m. EDT; Venus 4° south of the star Pollux.
31 Memorial Day (observed); Pluto at opposition; Mars 2° from Spica (quite close) and closing; this day in 1889, 2,207 killed in Johnstown, Pennsylvania, flood.