VOA科学技术2023--Super, Blue and Blood: A Guide to Different Full Moons

Super, Blue and Blood: A Guide to Different Full Moons

Sky watchers around the world were treated this month to two full moons, a supermoon and a blue moon.

The American space agency NASA explains a supermoon happens when the moon's orbit brings it closer than usual to Earth at the same time that the moon appears full from Earth. The first supermoon of 2023 was in July. The fourth and last one will be in September.

The last time two supermoons appeared in the sky in the same month was in 2018, The Associated Press reports. The next time a blue supermoon is set to arrive is 2037.

The first supermoon arrived on the first day of August, while the blue moon was seen beginning August 30. NASA noted¹ that when the blue moon arrived, the planet Saturn² was just a few days from its closest and brightest appearance of the year from Earth. Saturn appeared as a bright "star" to the upper right of the blue moon.

Italian astronomer³ Gianluca Masi, creator of the Virtual⁴ Telescope Project, held an online watch event as the blue supermoon was setting below the skyline of Rome. But he advised that, as long as the weather was good, world observers looking to the sky would not need any special equipment to see the moons.

"Warm summer nights are the ideal time to watch the full moon rise in the eastern sky within minutes of sunset," said retired⁵ NASA astrophysicist and moon expert Fred Espenak.

Full moons happen at the exact moment when the moon is opposite the sun, NASA says. Astronomers⁶ say a supermoon can appear about 14 percent larger and a bit brighter than other moons.

The Old Farmer's Almanac notes that the August full moon is known as the sturgeon moon. This is because of a traditionally large increase in fish in the American Great Lakes area during the month of August.

Although it is called a blue moon, it does not appear blue in color. Instead, the name means it is the second full moon to happen within one month or the fourth to take place in a season.

NASA says the moon takes 27.3 days to orbit Earth, but it takes 29.5 days to complete a full moon cycle. This is what makes it possible to see one full moon at the start of the month and another one right at the end.

Astronomers say, however, that the moon can look blue under the right conditions. For example, this can happen as a result of smoke or dust particles in the atmosphere.

While the blue supermoon brings the possibility for watching and taking beautiful pictures, its stronger gravitational pull also can influence higher tides. Weather experts advise people living in areas near shorelines to be aware of this, especially during storm activity.

There are other kinds of moons that appear at different times.

NASA says a blood moon happens during a total lunar eclipse⁷. This event is when Earth lines up between the moon and the sun, hiding the moon from sunlight. In addition, the term blood moon can also be used to describe a moon that appears reddish because of dust, smoke or haze⁸ particles in the sky.

A harvest moon is a full, bright moon that appears "closest to the start of autumn," NASA explains. This name dates from the time before electricity, when farmers depended on the moon's light to harvest their crops late into the night. The moon's light was especially important during fall when harvests are the largest.

Words in This Story

treat to –v. (phrasal) to give a person something that is pleasant, interesting or fun

eclipse – n. an event in which the sun is blocked by the moon, or when the moon passes through the Earth's shadow

haze – n. the appearance of air when it is not very clear because of the presence of heat, dust or smoke

1 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

2 Saturn   

n.农神，土星

参考例句：

• Astronomers used to ask why only Saturn has rings.天文学家们过去一直感到奇怪，为什么只有土星有光环。
• These comparisons suggested that Saturn is made of lighter materials.这些比较告诉我们，土星由较轻的物质构成。

3 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。

4 virtual   

adj.实质上的，事实上的，实际上的

参考例句：

• This reply is a virtual acceptance of our offer.这一回答实质上是接受了我们的建议。
• At that time the East India Company was the virtual ruler of Bengal.那时东印度公司是孟加拉的实际统治者。

5 retired   

adj.隐退的，退休的，退役的

参考例句：

• The old man retired to the country for rest.这位老人下乡休息去了。
• Many retired people take up gardening as a hobby.许多退休的人都以从事园艺为嗜好。

6 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

7 eclipse   

v.使黯然失色，使相形见绌，日食，月食

参考例句：

• During the seventies,her acting career was in eclipse.在七十年代，她的表演生涯黯然失色。
• There will be an eclipse of the moon next month.下个月有月食。

8 haze   

n.霾，烟雾；懵懂，迷糊；vi.(over)变模糊

参考例句：

• I couldn't see her through the haze of smoke.在烟雾弥漫中，我看不见她。
• He often lives in a haze of whisky.他常常是在威士忌的懵懂醉意中度过的。