Quick Answer
The outcome would depend overwhelmingly on the black hole’s mass and distance. A stellar-mass black hole far away could perturb Earth’s orbit without immediately swallowing the planet, while a sufficiently close or massive black hole would create extreme tidal forces and could destabilize the Solar System. A black hole is dangerous because of gravity and, for an accreting one, radiation — not because it is a cosmic vacuum cleaner.
The phrase “black hole appeared near Earth” hides the most important variables. A black hole can have the mass of a star or far more, and gravitational effects depend strongly on distance.
Would Earth be sucked in?
Not automatically. Outside a black hole, gravity follows the same basic inverse-square behavior as gravity from other masses. If the Sun were replaced by a black hole of exactly the same mass, Earth’s orbit would initially be almost unchanged; the loss of sunlight would be the immediate problem.
Tidal forces are the real danger
Close to a compact massive object, gravity can change dramatically over relatively short distances. Those differences produce tidal forces that can stretch and compress planets, moons and stars.
If it passed through the Solar System
A moving black hole could gravitationally scatter planets and smaller bodies. The exact result would depend on its mass, speed and trajectory. Even without a direct collision, a close encounter could change orbital paths.
Accretion and radiation
A black hole itself emits no ordinary light from inside its event horizon, but material falling toward it can form a hot accretion disk and produce intense radiation. A nearby active black hole could therefore be dangerous long before any gravitational capture.
Established scienceA black hole is not a magical suction point. Outside its event horizon, its gravitational field can be described using the same mass-and-distance principles that apply to other compact objects.
The bottom line
The phrase “near” is not enough to predict the outcome. A tiny black hole far away could be almost irrelevant, while a massive one close to Earth could destroy the Solar System’s current orbital structure.
A note on our approach: Every article on WhatIfLab separates what current science establishes from what remains genuinely speculative. Where we cite a figure or finding, it reflects published, mainstream research at the time of writing — not a prediction dressed up as fact.