What is perihelion and why does the Sun look bigger today?
On January 3, 2026, Earth reaches perihelion, the point in its orbit closest to the Sun. This annual event, part of a predictable celestial dance, isn’t dramatic in terms of distance—Earth comes within about 147 million kilometers (91 million miles) of the Sun—but it does have a noticeable effect on how large the Sun appears in our sky. For stargazers and casual observers alike, the Sun looks slightly larger and brighter for a day or two around this closest approach.
The science behind the distance
Earth orbits the Sun in an ellipse rather than a perfect circle. Because of this shape, there are two key moments to know: perihelion (closest) and aphelion (furthest). In 2026, perihelion occurs early in January, when the planet is about 147 to 147.5 million kilometers from the Sun. By contrast, aphelion—the farthest point—occurs around early July, about 152 million kilometers away. The roughly 3% difference in distance translates to a small but measurable change in the Sun’s apparent size and the solar energy reaching Earth.
How much bigger does the Sun look?
The Sun’s apparent diameter can vary by a fraction of a degree over the year due to orbital distance. At perihelion, the Sun’s angular diameter is about 32 arcminutes (about 0.53 degrees). A day or two around perihelion, you might notice the Sun looking a touch larger in the early morning or late afternoon. It’s a subtle effect, often most noticeable to photographers using long lenses or to careful observers comparing sunsets and sunrises across weeks.
What this means for our weather and environment
Despite appearing a bit brighter, perihelion does not dramatically alter Earth’s seasons. Those are driven primarily by the tilt of our planet’s axis, not the distance from the Sun. The slight increase in solar energy at perihelion is real but modest and quickly offset by the calendar-driven progression into winter or summer in different hemispheres. In practical terms, the momentary change is a reminder of the complex, dynamic relationship between Earth and its star.
How to observe safely and responsibly
There is no need for special equipment to notice the Sun’s size difference, but use safe viewing practices. Never look directly at the Sun without certified solar filters for any optical device. If you want to capture perihelion effects, consider setting up a time-lapse or a simple sequence of daily sunrises or sunsets, then compare the solar disc’s apparent size over a week or two. For most people, perihelion is a curiosity: a brief peak in our year-long cycle that underscores how our planet travels around a bright, constant star.
Historical context and upcoming perihelions
Perihelion is a predictable event that has been observed for centuries. Ancient observations of the Sun’s path helped early astronomers refine calendars and navigation. Today, spacecraft and satellites monitor solar distance and activity continually, but the naked-eye moment of perihelion remains a compelling reminder of our place in the solar system. The cycle repeats each year, with small variations due to the gravitational tug-of-war with other planets, particularly Jupiter and Saturn. In 2026, this annual milestone falls in early January, a useful anchor for amateur astronomers planning winter observing sessions.
Bottom line
Perihelion in 2026 brings Earth a touch closer to the Sun, making the solar disc appear slightly larger for a brief period. It’s a natural part of the annual orbit and a neat opportunity for skywatchers to note how even a small change in distance can influence our perception of the Sun. Whether you’re a casual observer or a seasoned photographer, the moment is a reminder to enjoy the cosmos’ regular rhythm and to keep safety first when observing our nearest star.
