LET Elementary Earth & Space Science Reviewer 2026

Answer: B. Mercury

Step 1 – Recall the order of planets from the Sun outward: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Step 2 – Mercury is listed first, making it the planet closest to the Sun. Step 3 – A common LET trap is confusing 'closest to the Sun' with 'hottest planet.' Venus is hotter than Mercury because its dense carbon-dioxide atmosphere traps heat (greenhouse effect), but Mercury is physically closer to the Sun. Step 4 – Remember: Closeness does not always mean hottest; atmosphere plays a big role in surface temperature.

Answer: C. Venus

Step 1 – Although Mercury is closest to the Sun, it has almost no atmosphere to hold heat. Step 2 – Venus has a very thick atmosphere made mostly of carbon dioxide, which acts like a blanket and traps solar heat. This is called the greenhouse effect. Step 3 – Because of this runaway greenhouse effect, Venus has surface temperatures around 465°C, making it hotter than Mercury. Step 4 – Mercury is NOT the hottest planet; Venus is. This is a very common LET misconception question. Step 5 – On the LET, always pair the concept of 'hottest planet' with 'thick CO₂ atmosphere' to arrive at Venus.

Answer: D. Jupiter

Step 1 – Jupiter is classified as a gas giant along with Saturn, Uranus, and Neptune. Step 2 – Among all eight planets, Jupiter has the greatest diameter and mass. It is so large that more than 1,300 Earths could fit inside it. Step 3 – Saturn is the second largest and is also famous for its bright ring system, but it is NOT the largest. Step 4 – Jupiter also has a distinctive feature called the Great Red Spot, which is a giant storm larger than Earth. Step 5 – A future elementary teacher should note that DepEd's K-12 science curriculum includes this concept in Grade 6 Earth Science.

Answer: B. The rotation of Earth on its own axis

Step 1 – Earth has two major motions: rotation (spinning on its axis) and revolution (orbiting the Sun). Step 2 – Rotation takes about 24 hours to complete one full spin, which is why we have a 24-hour day. Step 3 – The side of Earth facing the Sun experiences daytime; the side facing away experiences nighttime. Step 4 – Revolution causes the year (365.25 days) and contributes to seasons, but it does NOT cause day and night. Step 5 – Earth's axial tilt causes seasons, not day and night. These three causes (rotation, revolution, tilt) are often mixed up in LET items.

Answer: C. The tilt of Earth's axis as it revolves around the Sun

Step 1 – Earth's axis is tilted at about 23.5 degrees relative to its orbital plane. Step 2 – As Earth revolves around the Sun, one hemisphere tilts toward the Sun (receiving more direct sunlight and longer days = summer), while the other tilts away (receiving indirect sunlight and shorter days = winter). Step 3 – It is NOT the distance from the Sun that causes seasons; in fact, Earth is slightly closer to the Sun in January (Northern Hemisphere winter). Step 4 – In the Philippines, which lies near the equator, this axial tilt has a smaller effect, so we experience wet and dry seasons rather than four distinct temperate seasons. Step 5 – This is a top LET misconception item: always say 'axial tilt,' not 'distance from the Sun.'

Answer: B. New Moon

Step 1 – A solar eclipse happens when the Moon passes directly between the Sun and Earth, blocking the Sun's light from reaching parts of Earth. Step 2 – For the Moon to be between the Sun and Earth, it must be at the New Moon phase (the Moon is on the same side as the Sun). Step 3 – During a Full Moon, Earth is between the Sun and the Moon; this causes a LUNAR eclipse, not a solar one. Step 4 – Quarter moons have the Sun, Earth, and Moon forming a right angle, so no eclipse occurs. Step 5 – Memory tip: Solar eclipse = New Moon (Moon is between Sun and Earth). Lunar eclipse = Full Moon (Earth is between Sun and Moon).

Answer: B. It reflects sunlight toward Earth

Step 1 – Unlike the Sun, the Moon is not a star and does not undergo nuclear fusion, so it produces no light of its own. Step 2 – The Moon's surface reflects sunlight, and that reflected light reaches our eyes on Earth, making the Moon appear bright. Step 3 – The different Moon phases we observe (New, Crescent, Quarter, Gibbous, Full) are caused by how much of the Moon's sunlit side is visible from Earth as the Moon orbits. Step 4 – This concept is foundational for teaching Grade 6 pupils about the Earth-Moon-Sun system under the K-12 BEC science curriculum. Step 5 – Wrong options involve light production or absorption, which do not apply to the Moon.

Answer: B. The gravitational pull of the Moon on Earth's oceans

Step 1 – Tides are the periodic rise and fall of sea level. The Moon's gravity is the main force pulling Earth's ocean water toward the side of Earth closest to the Moon, creating a high tide. Step 2 – A corresponding high tide also forms on the opposite side of Earth due to inertia, while low tides form at the sides perpendicular to the Moon. Step 3 – The Sun also exerts a gravitational pull on Earth's oceans, but it is weaker than the Moon's influence on tides because the Moon is much closer to Earth. Step 4 – When the Sun and Moon align (at New and Full Moon), their combined gravity creates the largest tides, called spring tides. Step 5 – In the Philippines, fisher folk and coastal communities are very familiar with tidal patterns, making this a relatable real-world example for classroom teaching.

Answer: D. Blue

Step 1 – Stars emit light at different colors depending on their surface temperature, following the same principle as heated metal (which glows red, then orange, then white as it gets hotter). Step 2 – The temperature-color relationship for stars from hottest to coolest is: Blue → White → Yellow → Orange → Red. Step 3 – Blue stars are the HOTTEST; Red stars are the COOLEST. Step 4 – This reverses the everyday human intuition that 'red means hot' (as in a red traffic light or a red warning sign). The LET frequently tests this counterintuitive fact. Step 5 – Our Sun is a yellow star, which places it at a medium temperature among all stars.

Answer: B. The Big Bang Theory

Step 1 – The Big Bang Theory states that the universe began approximately 13.8 billion years ago from an extremely hot, dense state (a singularity) and has been expanding ever since. Step 2 – Two key pieces of evidence support it: (a) the redshift of distant galaxies (they are moving away from us, showing expansion) and (b) the cosmic microwave background radiation (a faint heat afterglow from the early universe). Step 3 – The Steady State Theory (an older, now rejected idea) proposed that the universe has always existed in the same form. Step 4 – The Nebular Theory explains the formation of the solar system from a cloud of gas and dust, not the origin of the entire universe. Step 5 – The Heliocentric Theory states that Earth revolves around the Sun, which is about our solar system, not the universe's origin.

Answer: A. Crust

Step 1: Recall the four main layers of the Earth from outside to inside: crust, mantle, outer core, and inner core. Step 2: The crust is the outermost rocky shell. It is only about 5–70 km thick, making it by far the thinnest layer. Step 3: The mantle is the thickest layer by volume, stretching about 2,900 km. The core makes up the center. Step 4: Why are the other options wrong? The mantle is the largest layer; the outer core and inner core are much deeper and are made of iron and nickel. Step 5: LET tip – a common trick is to confuse 'thinnest' with 'smallest'; remember the crust is thin like the skin of an apple.

Answer: B. Extreme pressure at the center keeps it solid.

Step 1: The inner core is hotter than the outer core, yet it remains solid. Step 2: High temperature alone would normally cause metal to melt, but the key factor here is pressure. Step 3: The weight of all overlying layers pushes down with enormous pressure at the Earth's center, compressing the iron-nickel material so tightly that it cannot flow like a liquid. Step 4: Why are the other options wrong? There is no special material – the inner core is iron and nickel, just like the outer core. Underground water does not reach the core. Iron and nickel are exactly what make up both core zones. Step 5: Remember: the outer core IS liquid, and its churning movement generates Earth's magnetic field.